CWE-78
AllowedImproper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Abstraction: Base · Status: Stable
The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.
8358 vulnerabilities reference this CWE, most recent first.
GHSA-3627-3986-7XVW
Vulnerability from github – Published: 2022-05-13 01:35 – Updated: 2022-05-13 01:35Multiple vulnerabilities in the CLI parser of Cisco IOS XE Software could allow an authenticated, local attacker to inject arbitrary commands into the CLI of the affected software, which could allow the attacker to gain access to the underlying Linux shell of an affected device and execute commands with root privileges on the device. The vulnerabilities exist because the affected software does not sufficiently sanitize command arguments before passing commands to the Linux shell for execution. An attacker could exploit these vulnerabilities by submitting a malicious CLI command to the affected software. A successful exploit could allow the attacker to break from the CLI of the affected software, which could allow the attacker to gain access to the underlying Linux shell on an affected device and execute arbitrary commands with root privileges on the device. Cisco Bug IDs: CSCuz03145, CSCuz56419, CSCva31971, CSCvb09542.
{
"affected": [],
"aliases": [
"CVE-2018-0193"
],
"database_specific": {
"cwe_ids": [
"CWE-78"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-03-28T22:29:00Z",
"severity": "HIGH"
},
"details": "Multiple vulnerabilities in the CLI parser of Cisco IOS XE Software could allow an authenticated, local attacker to inject arbitrary commands into the CLI of the affected software, which could allow the attacker to gain access to the underlying Linux shell of an affected device and execute commands with root privileges on the device. The vulnerabilities exist because the affected software does not sufficiently sanitize command arguments before passing commands to the Linux shell for execution. An attacker could exploit these vulnerabilities by submitting a malicious CLI command to the affected software. A successful exploit could allow the attacker to break from the CLI of the affected software, which could allow the attacker to gain access to the underlying Linux shell on an affected device and execute arbitrary commands with root privileges on the device. Cisco Bug IDs: CSCuz03145, CSCuz56419, CSCva31971, CSCvb09542.",
"id": "GHSA-3627-3986-7xvw",
"modified": "2022-05-13T01:35:40Z",
"published": "2022-05-13T01:35:40Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-0193"
},
{
"type": "WEB",
"url": "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-cmdinj"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/103547"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-362G-878V-39VP
Vulnerability from github – Published: 2023-11-03 06:36 – Updated: 2023-11-13 21:30ASUS RT-AC86U’s authentication-related function has a vulnerability of insufficient filtering of special characters within its code-authentication module. An authenticated remote attacker can exploit this vulnerability to perform a Command Injection attack to execute arbitrary commands, disrupt the system or terminate services.
{
"affected": [],
"aliases": [
"CVE-2023-41348"
],
"database_specific": {
"cwe_ids": [
"CWE-78"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-11-03T05:15:29Z",
"severity": "HIGH"
},
"details": "ASUS RT-AC86U\u2019s authentication-related function has a vulnerability of insufficient filtering of special characters within its code-authentication module. An authenticated remote attacker can exploit this vulnerability to perform a Command Injection attack to execute arbitrary commands, disrupt the system or terminate services.",
"id": "GHSA-362g-878v-39vp",
"modified": "2023-11-13T21:30:56Z",
"published": "2023-11-03T06:36:30Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-41348"
},
{
"type": "WEB",
"url": "https://www.twcert.org.tw/tw/cp-132-7499-63907-1.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-363Q-XRJC-RQPJ
Vulnerability from github – Published: 2026-07-03 15:31 – Updated: 2026-07-03 15:31Dell PowerProtect Data Domain, versions 7.7.1.0 through 8.7, LTS2026 release version 8.6.1.0 through 8.6.1.10, LTS2025 release version 8.3.1.0 through 8.3.1.30, LTS2024 release versions 7.13.1.0 through 7.13.1.70 contain an improper neutralization of special Elements used in an OS command ('OS command Injection') vulnerability. A high privileged attacker with remote access could potentially exploit this vulnerability, leading to execution of arbitrary OS commands.
{
"affected": [],
"aliases": [
"CVE-2026-49815"
],
"database_specific": {
"cwe_ids": [
"CWE-78"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-03T15:16:32Z",
"severity": "HIGH"
},
"details": "Dell PowerProtect Data Domain, versions 7.7.1.0 through 8.7, LTS2026 release version 8.6.1.0 through 8.6.1.10, LTS2025 release version 8.3.1.0 through 8.3.1.30, LTS2024 release versions 7.13.1.0 through 7.13.1.70 contain an improper neutralization of special Elements used in an OS command (\u0027OS command Injection\u0027) vulnerability. A high privileged attacker with remote access could potentially exploit this vulnerability, leading to execution of arbitrary OS commands.",
"id": "GHSA-363q-xrjc-rqpj",
"modified": "2026-07-03T15:31:59Z",
"published": "2026-07-03T15:31:59Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-49815"
},
{
"type": "WEB",
"url": "https://www.dell.com/support/kbdoc/en-us/000481268/dsa-2026-278-security-update-for-dell-powerprotect-data-domain-multiple-vulnerabilities"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-364C-G6GQ-6JW3
Vulnerability from github – Published: 2024-08-27 18:31 – Updated: 2024-08-27 21:31D-Link DIR-846W A1 FW100A43 was discovered to contain a remote command execution (RCE) vulnerability via keys smartqos_express_devices and smartqos_normal_devices in SetSmartQoSSettings.
{
"affected": [],
"aliases": [
"CVE-2024-44340"
],
"database_specific": {
"cwe_ids": [
"CWE-78"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-08-27T16:15:07Z",
"severity": "HIGH"
},
"details": "D-Link DIR-846W A1 FW100A43 was discovered to contain a remote command execution (RCE) vulnerability via keys smartqos_express_devices and smartqos_normal_devices in SetSmartQoSSettings.",
"id": "GHSA-364c-g6gq-6jw3",
"modified": "2024-08-27T21:31:13Z",
"published": "2024-08-27T18:31:37Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-44340"
},
{
"type": "WEB",
"url": "https://github.com/yali-1002/some-poc/blob/main/CVE-2024-44340"
},
{
"type": "WEB",
"url": "https://www.dlink.com/en/security-bulletin"
},
{
"type": "WEB",
"url": "http://www.dlink.com.cn/techsupport/ProductInfo.aspx?m=DIR-846W"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-365G-VJW2-GRX8
Vulnerability from github – Published: 2025-10-09 15:26 – Updated: 2025-10-09 15:27Impact
The Execute Command node in n8n allows execution of arbitrary commands on the host system where n8n runs. While this functionality is intended for advanced automation and can be useful in certain workflows, it poses a security risk if all users with access to the n8n instance are not fully trusted.
An attacker—either a malicious user or someone who has compromised a legitimate user account—could exploit this node to run arbitrary commands on the host machine, potentially leading to data exfiltration, service disruption, or full system compromise.
This vulnerability affects all n8n deployments where:
- The
Execute Commandnode is enabled, and - Not all user accounts are strictly controlled and trusted.
n8n.cloud is not impacted.
Patches
No code changes have been made to alter the behavior of the Execute Command node. The recommended mitigation is to disable the node by default in environments where it is not explicitly required.
Future n8n versions may change the default availability of this node.
Workarounds
Administrators can disable the Execute Command node by setting the following environment variable before starting n8n:
export NODES_EXCLUDE: "[\"n8n-nodes-base.executeCommand\"]"
References
n8n docs: Execute Command n8n docs: Blocking nodes
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "n8n-nodes-base"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"last_affected": "1.113.0"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "n8n"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"last_affected": "1.114.4"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-78"
],
"github_reviewed": true,
"github_reviewed_at": "2025-10-09T15:26:59Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "### Impact\n\nThe `Execute Command` node in n8n allows execution of arbitrary commands on the host system where n8n runs. While this functionality is intended for advanced automation and can be useful in certain workflows, it poses a security risk if all users with access to the n8n instance are not fully trusted.\n\nAn attacker\u2014either a malicious user or someone who has compromised a legitimate user account\u2014could exploit this node to run arbitrary commands on the host machine, potentially leading to data exfiltration, service disruption, or full system compromise.\n\nThis vulnerability affects all n8n deployments where:\n\n- The `Execute Command` node is enabled, and\n- Not all user accounts are strictly controlled and trusted.\n\nn8n.cloud is **not** impacted.\n\n\n### Patches\nNo code changes have been made to alter the behavior of the `Execute Command` node. The recommended mitigation is to disable the node by default in environments where it is not explicitly required.\n\nFuture n8n versions may change the default availability of this node.\n\n### Workarounds\nAdministrators can disable the `Execute Command` node by setting the following environment variable before starting n8n:\n\n```bash\nexport NODES_EXCLUDE: \"[\\\"n8n-nodes-base.executeCommand\\\"]\"\n```\n\n### References\nn8n docs: [Execute Command](https://docs.n8n.io/integrations/builtin/core-nodes/n8n-nodes-base.executecommand/)\nn8n docs: [Blocking nodes](https://docs.n8n.io/hosting/securing/blocking-nodes/)",
"id": "GHSA-365g-vjw2-grx8",
"modified": "2025-10-09T15:27:00Z",
"published": "2025-10-09T15:26:59Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/n8n-io/n8n/security/advisories/GHSA-365g-vjw2-grx8"
},
{
"type": "PACKAGE",
"url": "https://github.com/n8n-io/n8n"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "n8n: Execute Command Node Allows Authenticated Users to Run Arbitrary Commands on Host"
}
GHSA-3672-644Q-JCFR
Vulnerability from github – Published: 2022-05-24 22:28 – Updated: 2022-10-08 00:00Multiple camera devices by UDP Technology, Geutebrück and other vendors are vulnerable to command injection, which may allow an attacker to remotely execute arbitrary code.
{
"affected": [],
"aliases": [
"CVE-2021-33551"
],
"database_specific": {
"cwe_ids": [
"CWE-77",
"CWE-78"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-09-13T18:15:00Z",
"severity": "HIGH"
},
"details": "Multiple camera devices by UDP Technology, Geutebr\u00c3\u00bcck and other vendors are vulnerable to command injection, which may allow an attacker to remotely execute arbitrary code.",
"id": "GHSA-3672-644q-jcfr",
"modified": "2022-10-08T00:00:17Z",
"published": "2022-05-24T22:28:06Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-33551"
},
{
"type": "WEB",
"url": "https://us-cert.cisa.gov/ics/advisories/icsa-21-208-03"
},
{
"type": "WEB",
"url": "https://www.randorisec.fr/fr/udp-technology-ip-camera-vulnerabilities"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-3679-H6WQ-5H4C
Vulnerability from github – Published: 2022-05-24 17:20 – Updated: 2022-05-24 17:20Certain NETGEAR devices are affected by command injection by an unauthenticated attacker. This affects RBK752 before 3.2.15.25, RBK753 before 3.2.15.25, RBK753S before 3.2.15.25, RBR750 before 3.2.15.25, RBS750 before 3.2.15.25, RBK842 before 3.2.15.25, RBR840 before 3.2.15.25, RBS840 before 3.2.15.25, RBK852 before 3.2.15.25, RBK853 before 3.2.15.25, RBR850 before 3.2.15.25, and RBS850 before 3.2.15.25.
{
"affected": [],
"aliases": [
"CVE-2020-14439"
],
"database_specific": {
"cwe_ids": [
"CWE-78"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2020-06-18T17:15:00Z",
"severity": "MODERATE"
},
"details": "Certain NETGEAR devices are affected by command injection by an unauthenticated attacker. This affects RBK752 before 3.2.15.25, RBK753 before 3.2.15.25, RBK753S before 3.2.15.25, RBR750 before 3.2.15.25, RBS750 before 3.2.15.25, RBK842 before 3.2.15.25, RBR840 before 3.2.15.25, RBS840 before 3.2.15.25, RBK852 before 3.2.15.25, RBK853 before 3.2.15.25, RBR850 before 3.2.15.25, and RBS850 before 3.2.15.25.",
"id": "GHSA-3679-h6wq-5h4c",
"modified": "2022-05-24T17:20:54Z",
"published": "2022-05-24T17:20:54Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-14439"
},
{
"type": "WEB",
"url": "https://kb.netgear.com/000061942/Security-Advisory-for-Pre-Authentication-Command-Injection-on-Some-WiFi-Systems-PSV-2020-0064"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-369H-6J28-WWCG
Vulnerability from github – Published: 2025-09-15 12:31 – Updated: 2025-09-15 21:07The cleanTcs mutation in Chaos Controller Manager is vulnerable to OS command injection. In conjunction with CVE-2025-59358, this allows unauthenticated in-cluster attackers to perform remote code execution across the cluster.
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/chaos-mesh/chaos-mesh"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.7.3"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-59359"
],
"database_specific": {
"cwe_ids": [
"CWE-78"
],
"github_reviewed": true,
"github_reviewed_at": "2025-09-15T21:07:16Z",
"nvd_published_at": "2025-09-15T12:15:33Z",
"severity": "CRITICAL"
},
"details": "The cleanTcs mutation in Chaos Controller Manager is vulnerable to OS command injection. In conjunction with CVE-2025-59358, this allows unauthenticated in-cluster attackers to perform remote code execution across the cluster.",
"id": "GHSA-369h-6j28-wwcg",
"modified": "2025-09-15T21:07:16Z",
"published": "2025-09-15T12:31:25Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-59359"
},
{
"type": "WEB",
"url": "https://github.com/chaos-mesh/chaos-mesh/pull/4702"
},
{
"type": "WEB",
"url": "https://github.com/chaos-mesh/chaos-mesh/commit/67281c36f8068bf103149318cd0a466417213a28"
},
{
"type": "PACKAGE",
"url": "https://github.com/chaos-mesh/chaos-mesh"
},
{
"type": "WEB",
"url": "https://jfrog.com/blog/chaotic-deputy-critical-vulnerabilities-in-chaos-mesh-lead-to-kubernetes-cluster-takeover"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "Chaos Controller Manager is vulnerable to OS command injection"
}
GHSA-36P8-MVP6-CV38
Vulnerability from github – Published: 2026-01-21 23:00 – Updated: 2026-01-21 23:00Summary
A command injection vulnerability (CWE-78) has been found to exist in the wrangler pages deploy command. The issue occurs because the --commit-hash parameter is passed directly to a shell command without proper validation or sanitization, allowing an attacker with control of --commit-hash to execute arbitrary commands on the system running Wrangler.
Root cause
The commitHash variable, derived from user input via the --commit-hash CLI argument, is interpolated directly into a shell command using template literals (e.g., execSync(`git show -s --format=%B ${commitHash}`)). Shell metacharacters are interpreted by the shell, enabling command execution.
Impact
This vulnerability is generally hard to exploit, as it requires --commit-hash to be attacker controlled. The vulnerability primarily affects CI/CD environments where wrangler pages deploy is used in automated pipelines and the --commit-hash parameter is populated from external, potentially untrusted sources. An attacker could exploit this to:
- Run any shell command.
- Exfiltrate environment variables.
- Compromise the CI runner to install backdoors or modify build artifacts.
Mitigation
- Wrangler v4 users are requested to upgrade to Wrangler v4.59.1 or higher.
- Wrangler v3 users are requested to upgrade to Wrangler v3.114.17 or higher.
- Users on Wrangler v2 (EOL) should upgrade to a supported major version.
Credits
Disclosed responsibly by kny4hacker.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "wrangler"
},
"ranges": [
{
"events": [
{
"introduced": "2.0.15"
},
{
"fixed": "3.114.17"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "wrangler"
},
"ranges": [
{
"events": [
{
"introduced": "4.0.0"
},
{
"fixed": "4.59.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-0933"
],
"database_specific": {
"cwe_ids": [
"CWE-78"
],
"github_reviewed": true,
"github_reviewed_at": "2026-01-21T23:00:35Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "**Summary**\n\nA command injection vulnerability (CWE-78) has been found to exist in the `wrangler pages deploy` command. The issue occurs because the `--commit-hash` parameter is passed directly to a shell command without proper validation or sanitization, allowing an attacker with control of `--commit-hash` to execute arbitrary commands on the system running Wrangler.\n\n**Root cause**\n\nThe `commitHash` variable, derived from user input via the `--commit-hash` CLI argument, is interpolated directly into a shell command using template literals (e.g., ``execSync(`git show -s --format=%B ${commitHash}`)``). Shell metacharacters are interpreted by the shell, enabling command execution.\n\n**Impact**\n\nThis vulnerability is generally hard to exploit, as it requires `--commit-hash` to be attacker controlled. The vulnerability primarily affects CI/CD environments where `wrangler pages deploy` is used in automated pipelines and the `--commit-hash` parameter is populated from external, potentially untrusted sources. An attacker could exploit this to:\n\n- Run any shell command.\n- Exfiltrate environment variables.\n- Compromise the CI runner to install backdoors or modify build artifacts.\n\n**Mitigation**\n\n- Wrangler v4 users are requested to upgrade to Wrangler v4.59.1 or higher. \n- Wrangler v3 users are requested to upgrade to Wrangler v3.114.17 or higher. \n- Users on Wrangler v2 (EOL) should upgrade to a supported major version.\n\n**Credits**\n\nDisclosed responsibly by kny4hacker.",
"id": "GHSA-36p8-mvp6-cv38",
"modified": "2026-01-21T23:00:35Z",
"published": "2026-01-21T23:00:35Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/cloudflare/workers-sdk/security/advisories/GHSA-36p8-mvp6-cv38"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-0933"
},
{
"type": "WEB",
"url": "https://github.com/cloudflare/workers-sdk/commit/99b1f328a9afe181b49f1114ed47f15f6d25f0be"
},
{
"type": "PACKAGE",
"url": "https://github.com/cloudflare/workers-sdk"
},
{
"type": "WEB",
"url": "https://github.com/cloudflare/workers-sdk/releases/tag/wrangler%403.114.17"
},
{
"type": "WEB",
"url": "https://github.com/cloudflare/workers-sdk/releases/tag/wrangler%404.59.1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Wrangler affected by OS Command Injection in `wrangler pages deploy`"
}
GHSA-36R9-R78P-JQG9
Vulnerability from github – Published: 2022-05-13 01:01 – Updated: 2022-05-13 01:01An exploitable vulnerability exists in the /api/CONFIG/restore functionality of Circle with Disney running firmware 2.0.1. Specially crafted network packets can cause an OS command injection. An attacker can send an HTTP request trigger this vulnerability.
{
"affected": [],
"aliases": [
"CVE-2017-2890"
],
"database_specific": {
"cwe_ids": [
"CWE-78"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2017-11-07T16:29:00Z",
"severity": "HIGH"
},
"details": "An exploitable vulnerability exists in the /api/CONFIG/restore functionality of Circle with Disney running firmware 2.0.1. Specially crafted network packets can cause an OS command injection. An attacker can send an HTTP request trigger this vulnerability.",
"id": "GHSA-36r9-r78p-jqg9",
"modified": "2022-05-13T01:01:16Z",
"published": "2022-05-13T01:01:16Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2017-2890"
},
{
"type": "WEB",
"url": "https://www.talosintelligence.com/vulnerability_reports/TALOS-2017-0397"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Mitigation
If at all possible, use library calls rather than external processes to recreate the desired functionality.
Mitigation MIT-22
Strategy: Sandbox or Jail
- Run the code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software.
- OS-level examples include the Unix chroot jail, AppArmor, and SELinux. In general, managed code may provide some protection. For example, java.io.FilePermission in the Java SecurityManager allows the software to specify restrictions on file operations.
- This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise.
- Be careful to avoid CWE-243 and other weaknesses related to jails.
Mitigation
Strategy: Attack Surface Reduction
For any data that will be used to generate a command to be executed, keep as much of that data out of external control as possible. For example, in web applications, this may require storing the data locally in the session's state instead of sending it out to the client in a hidden form field.
Mitigation MIT-15
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
Mitigation MIT-4.3
Strategy: Libraries or Frameworks
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- For example, consider using the ESAPI Encoding control [REF-45] or a similar tool, library, or framework. These will help the programmer encode outputs in a manner less prone to error.
Mitigation MIT-28
Strategy: Output Encoding
While it is risky to use dynamically-generated query strings, code, or commands that mix control and data together, sometimes it may be unavoidable. Properly quote arguments and escape any special characters within those arguments. The most conservative approach is to escape or filter all characters that do not pass an extremely strict allowlist (such as everything that is not alphanumeric or white space). If some special characters are still needed, such as white space, wrap each argument in quotes after the escaping/filtering step. Be careful of argument injection (CWE-88).
Mitigation
If the program to be executed allows arguments to be specified within an input file or from standard input, then consider using that mode to pass arguments instead of the command line.
Mitigation MIT-27
Strategy: Parameterization
- If available, use structured mechanisms that automatically enforce the separation between data and code. These mechanisms may be able to provide the relevant quoting, encoding, and validation automatically, instead of relying on the developer to provide this capability at every point where output is generated.
- Some languages offer multiple functions that can be used to invoke commands. Where possible, identify any function that invokes a command shell using a single string, and replace it with a function that requires individual arguments. These functions typically perform appropriate quoting and filtering of arguments. For example, in C, the system() function accepts a string that contains the entire command to be executed, whereas execl(), execve(), and others require an array of strings, one for each argument. In Windows, CreateProcess() only accepts one command at a time. In Perl, if system() is provided with an array of arguments, then it will quote each of the arguments.
Mitigation MIT-5
Strategy: Input Validation
- Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
- When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue."
- Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
- When constructing OS command strings, use stringent allowlists that limit the character set based on the expected value of the parameter in the request. This will indirectly limit the scope of an attack, but this technique is less important than proper output encoding and escaping.
- Note that proper output encoding, escaping, and quoting is the most effective solution for preventing OS command injection, although input validation may provide some defense-in-depth. This is because it effectively limits what will appear in output. Input validation will not always prevent OS command injection, especially if you are required to support free-form text fields that could contain arbitrary characters. For example, when invoking a mail program, you might need to allow the subject field to contain otherwise-dangerous inputs like ";" and ">" characters, which would need to be escaped or otherwise handled. In this case, stripping the character might reduce the risk of OS command injection, but it would produce incorrect behavior because the subject field would not be recorded as the user intended. This might seem to be a minor inconvenience, but it could be more important when the program relies on well-structured subject lines in order to pass messages to other components.
- Even if you make a mistake in your validation (such as forgetting one out of 100 input fields), appropriate encoding is still likely to protect you from injection-based attacks. As long as it is not done in isolation, input validation is still a useful technique, since it may significantly reduce your attack surface, allow you to detect some attacks, and provide other security benefits that proper encoding does not address.
Mitigation MIT-21
Strategy: Enforcement by Conversion
When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
Mitigation MIT-32
Strategy: Compilation or Build Hardening
Run the code in an environment that performs automatic taint propagation and prevents any command execution that uses tainted variables, such as Perl's "-T" switch. This will force the program to perform validation steps that remove the taint, although you must be careful to correctly validate your inputs so that you do not accidentally mark dangerous inputs as untainted (see CWE-183 and CWE-184).
Mitigation MIT-32
Strategy: Environment Hardening
Run the code in an environment that performs automatic taint propagation and prevents any command execution that uses tainted variables, such as Perl's "-T" switch. This will force the program to perform validation steps that remove the taint, although you must be careful to correctly validate your inputs so that you do not accidentally mark dangerous inputs as untainted (see CWE-183 and CWE-184).
Mitigation MIT-39
- Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success.
- If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files.
- Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not.
- In the context of OS Command Injection, error information passed back to the user might reveal whether an OS command is being executed and possibly which command is being used.
Mitigation
Strategy: Sandbox or Jail
Use runtime policy enforcement to create an allowlist of allowable commands, then prevent use of any command that does not appear in the allowlist. Technologies such as AppArmor are available to do this.
Mitigation MIT-29
Strategy: Firewall
Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].
Mitigation MIT-17
Strategy: Environment Hardening
Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
Mitigation MIT-16
Strategy: Environment Hardening
When using PHP, configure the application so that it does not use register_globals. During implementation, develop the application so that it does not rely on this feature, but be wary of implementing a register_globals emulation that is subject to weaknesses such as CWE-95, CWE-621, and similar issues.
CAPEC-108: Command Line Execution through SQL Injection
An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.
CAPEC-15: Command Delimiters
An attack of this type exploits a programs' vulnerabilities that allows an attacker's commands to be concatenated onto a legitimate command with the intent of targeting other resources such as the file system or database. The system that uses a filter or denylist input validation, as opposed to allowlist validation is vulnerable to an attacker who predicts delimiters (or combinations of delimiters) not present in the filter or denylist. As with other injection attacks, the attacker uses the command delimiter payload as an entry point to tunnel through the application and activate additional attacks through SQL queries, shell commands, network scanning, and so on.
CAPEC-43: Exploiting Multiple Input Interpretation Layers
An attacker supplies the target software with input data that contains sequences of special characters designed to bypass input validation logic. This exploit relies on the target making multiples passes over the input data and processing a "layer" of special characters with each pass. In this manner, the attacker can disguise input that would otherwise be rejected as invalid by concealing it with layers of special/escape characters that are stripped off by subsequent processing steps. The goal is to first discover cases where the input validation layer executes before one or more parsing layers. That is, user input may go through the following logic in an application: <parser1> --> <input validator> --> <parser2>. In such cases, the attacker will need to provide input that will pass through the input validator, but after passing through parser2, will be converted into something that the input validator was supposed to stop.
CAPEC-6: Argument Injection
An attacker changes the behavior or state of a targeted application through injecting data or command syntax through the targets use of non-validated and non-filtered arguments of exposed services or methods.
CAPEC-88: OS Command Injection
In this type of an attack, an adversary injects operating system commands into existing application functions. An application that uses untrusted input to build command strings is vulnerable. An adversary can leverage OS command injection in an application to elevate privileges, execute arbitrary commands and compromise the underlying operating system.