CWE-22
Allowed-with-ReviewImproper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Abstraction: Base · Status: Stable
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
13017 vulnerabilities reference this CWE, most recent first.
GHSA-XM77-R4GQ-GM87
Vulnerability from github – Published: 2022-05-24 19:12 – Updated: 2022-05-24 19:12Directory Traversal vulnerability exists in PopojiCMS 2.0.1 via the id parameter in admin.php.
{
"affected": [],
"aliases": [
"CVE-2020-19547"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-08-25T20:15:00Z",
"severity": "MODERATE"
},
"details": "Directory Traversal vulnerability exists in PopojiCMS 2.0.1 via the id parameter in admin.php.",
"id": "GHSA-xm77-r4gq-gm87",
"modified": "2022-05-24T19:12:09Z",
"published": "2022-05-24T19:12:09Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-19547"
},
{
"type": "WEB",
"url": "https://github.com/PopojiCMS/PopojiCMS/issues/19"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-XM92-RF24-H74W
Vulnerability from github – Published: 2022-05-14 02:40 – Updated: 2024-02-26 22:14Multiple directory traversal vulnerabilities in the web administration console in Apache Geronimo Application Server 2.1 through 2.1.3 on Windows allow remote attackers to upload files to arbitrary directories via directory traversal sequences in the (1) group, (2) artifact, (3) version, or (4) fileType parameter to console/portal//Services/Repository (aka the Services/Repository portlet); the (5) createDB parameter to console/portal/Embedded DB/DB Manager (aka the Embedded DB/DB Manager portlet); or the (6) filename parameter to the createKeystore script in the Security/Keystores portlet.
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "org.apache.geronimo.plugins:console"
},
"ranges": [
{
"events": [
{
"introduced": "2.1.0"
},
{
"fixed": "2.1.4"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2008-5518"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2024-02-26T22:14:31Z",
"nvd_published_at": "2009-04-17T14:30:00Z",
"severity": "HIGH"
},
"details": "Multiple directory traversal vulnerabilities in the web administration console in Apache Geronimo Application Server 2.1 through 2.1.3 on Windows allow remote attackers to upload files to arbitrary directories via directory traversal sequences in the (1) group, (2) artifact, (3) version, or (4) fileType parameter to console/portal//Services/Repository (aka the Services/Repository portlet); the (5) createDB parameter to console/portal/Embedded DB/DB Manager (aka the Embedded DB/DB Manager portlet); or the (6) filename parameter to the createKeystore script in the Security/Keystores portlet.",
"id": "GHSA-xm92-rf24-h74w",
"modified": "2024-02-26T22:14:31Z",
"published": "2022-05-14T02:40:10Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2008-5518"
},
{
"type": "WEB",
"url": "https://github.com/apache/geronimo/commit/aa0c2c26dde8930cad924796af7c17a13d236b16"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/49898"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/49899"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/49900"
},
{
"type": "PACKAGE",
"url": "https://github.com/apache/geronimo"
},
{
"type": "WEB",
"url": "https://web.archive.org/web/20090419162753/http://secunia.com/advisories/34715"
},
{
"type": "WEB",
"url": "https://web.archive.org/web/20090422192030/http://dsecrg.com/pages/vul/show.php?id=118"
},
{
"type": "WEB",
"url": "https://web.archive.org/web/20200229223125/http://www.securityfocus.com/bid/34562"
},
{
"type": "WEB",
"url": "https://www.exploit-db.com/exploits/8458"
},
{
"type": "WEB",
"url": "http://geronimo.apache.org/21x-security-report.html#2.1.xSecurityReport-214"
},
{
"type": "WEB",
"url": "http://issues.apache.org/jira/browse/GERONIMO-4597"
}
],
"schema_version": "1.4.0",
"severity": [],
"summary": "Apache Geronimo Application Server multiple directory traversal vulnerabilities"
}
GHSA-XM96-GFJX-JCRC
Vulnerability from github – Published: 2026-05-19 15:47 – Updated: 2026-05-19 15:47Summary
The pullArtifact methods in Registry and OCILayout use the org.opencontainers.image.title annotation from a pulled manifest as a filename, resolving it against the caller supplied output directory without normalization or a containment check. A manifest publisher can set this annotation to a path that escapes the output directory, causing the SDK to write the layer's blob anywhere the JVM process can write.
Details
Two call sites are affected.
src/main/java/land/oras/Registry.java, pullLayer (reached from Registry.pullArtifact):
Path targetPath = path.resolve(layer.getAnnotations().get(Const.ANNOTATION_TITLE));
...
Files.copy(is, targetPath, StandardCopyOption.REPLACE_EXISTING);
src/main/java/land/oras/OCILayout.java, OCILayout.pullArtifact:
Files.copy(blobPath, path.resolve(layer.getAnnotations().get(Const.ANNOTATION_TITLE)));
The annotation comes from the remote manifest. Path.resolve treats an absolute argument as a full override of the base, and follows .. segments upward, so the annotation controls the destination. REPLACE_EXISTING overwrites files that exist at that destination.
The unpack branch of pullLayer (taken when the layer carries io.deis.oras.content.unpack=true) is not affected, because it dispatches through ArchiveUtils.untar / unzip, which apply outputPath.startsWith(normalizedTarget) after normalization. The non unpack branch and OCILayout.pullArtifact lack the equivalent check.
fetchBlob(ContainerRef, Path) is not affected. The caller passes the destination path and the title annotation is not consulted.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 0.6.1"
},
"package": {
"ecosystem": "Maven",
"name": "land.oras:oras-java-sdk"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.6.2"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2026-05-19T15:47:36Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "### Summary\n\nThe `pullArtifact` methods in `Registry` and `OCILayout` use the `org.opencontainers.image.title` annotation from a pulled manifest as a filename, resolving it against the caller supplied output directory without normalization or a containment check. A manifest publisher can set this annotation to a path that escapes the output directory, causing the SDK to write the layer\u0027s blob anywhere the JVM process can write.\n\n### Details\n\nTwo call sites are affected.\n\n`src/main/java/land/oras/Registry.java`, `pullLayer` (reached from `Registry.pullArtifact`):\n\n```java\nPath targetPath = path.resolve(layer.getAnnotations().get(Const.ANNOTATION_TITLE));\n...\nFiles.copy(is, targetPath, StandardCopyOption.REPLACE_EXISTING);\n```\n\n`src/main/java/land/oras/OCILayout.java`, `OCILayout.pullArtifact`:\n\n```java\nFiles.copy(blobPath, path.resolve(layer.getAnnotations().get(Const.ANNOTATION_TITLE)));\n```\n\nThe annotation comes from the remote manifest. `Path.resolve` treats an absolute argument as a full override of the base, and follows `..` segments upward, so the annotation controls the destination. `REPLACE_EXISTING` overwrites files that exist at that destination.\n\nThe unpack branch of `pullLayer` (taken when the layer carries `io.deis.oras.content.unpack=true`) is not affected, because it dispatches through `ArchiveUtils.untar` / `unzip`, which apply `outputPath.startsWith(normalizedTarget)` after normalization. The non unpack branch and `OCILayout.pullArtifact` lack the equivalent check.\n\n`fetchBlob(ContainerRef, Path)` is not affected. The caller passes the destination path and the title annotation is not consulted.",
"id": "GHSA-xm96-gfjx-jcrc",
"modified": "2026-05-19T15:47:36Z",
"published": "2026-05-19T15:47:36Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/oras-project/oras-java/security/advisories/GHSA-xm96-gfjx-jcrc"
},
{
"type": "PACKAGE",
"url": "https://github.com/oras-project/oras-java"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "ORAS Java: Path traversal in pullArtifact via attacker-controlled org.opencontainers.image.title annotation"
}
GHSA-XMC5-7CWW-2H26
Vulnerability from github – Published: 2022-02-12 00:00 – Updated: 2022-02-24 00:01A CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability exists that could allow a remote code execution when a file is saved. Affected Product: C-Bus Toolkit (V1.15.9 and prior), C-Gate Server (V2.11.7 and prior)
{
"affected": [],
"aliases": [
"CVE-2021-22748"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-02-11T18:15:00Z",
"severity": "HIGH"
},
"details": "A CWE-22: Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027) vulnerability exists that could allow a remote code execution when a file is saved. Affected Product: C-Bus Toolkit (V1.15.9 and prior), C-Gate Server (V2.11.7 and prior)",
"id": "GHSA-xmc5-7cww-2h26",
"modified": "2022-02-24T00:01:20Z",
"published": "2022-02-12T00:00:45Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-22748"
},
{
"type": "WEB",
"url": "http://download.schneider-electric.com/files?p_Doc_Ref=SEVD-2021-103-01"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-XMCG-5RVR-G4J6
Vulnerability from github – Published: 2022-05-13 01:07 – Updated: 2022-05-13 01:07A path traversal vulnerability was identified in the Cloud Foundry component Cloud Controller that affects cf-release versions prior to v208 and Pivotal Cloud Foundry Elastic Runtime versions prior to 1.4.2. Path traversal is the 'outbreak' of a given directory structure through relative file paths in the user input. It aims at accessing files and directories that are stored outside the web root folder, for disallowed reading or even executing arbitrary system commands. An attacker could use a certain parameter of the file path for instance to inject '../' sequences in order to navigate through the file system. In this particular case a remote authenticated attacker can exploit the identified vulnerability in order to upload arbitrary files to the server running a Cloud Controller instance - outside the isolated application container.
{
"affected": [],
"aliases": [
"CVE-2015-1834"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2017-05-25T17:29:00Z",
"severity": "MODERATE"
},
"details": "A path traversal vulnerability was identified in the Cloud Foundry component Cloud Controller that affects cf-release versions prior to v208 and Pivotal Cloud Foundry Elastic Runtime versions prior to 1.4.2. Path traversal is the \u0027outbreak\u0027 of a given directory structure through relative file paths in the user input. It aims at accessing files and directories that are stored outside the web root folder, for disallowed reading or even executing arbitrary system commands. An attacker could use a certain parameter of the file path for instance to inject \u0027../\u0027 sequences in order to navigate through the file system. In this particular case a remote authenticated attacker can exploit the identified vulnerability in order to upload arbitrary files to the server running a Cloud Controller instance - outside the isolated application container.",
"id": "GHSA-xmcg-5rvr-g4j6",
"modified": "2022-05-13T01:07:02Z",
"published": "2022-05-13T01:07:02Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2015-1834"
},
{
"type": "WEB",
"url": "https://pivotal.io/security/cve-2015-1834"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/98691"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-XMCM-4QR4-5MMQ
Vulnerability from github – Published: 2022-05-17 01:40 – Updated: 2022-05-17 01:40Directory traversal vulnerability in HServer 0.1.1 allows remote attackers to read arbitrary files via a (1) ..%5c (dot dot encoded backslash) or (2) %2e%2e%5c (encoded dot dot backslash) in the PATH_INFO.
{
"affected": [],
"aliases": [
"CVE-2012-5100"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2012-09-23T17:55:00Z",
"severity": "MODERATE"
},
"details": "Directory traversal vulnerability in HServer 0.1.1 allows remote attackers to read arbitrary files via a (1) ..%5c (dot dot encoded backslash) or (2) %2e%2e%5c (encoded dot dot backslash) in the PATH_INFO.",
"id": "GHSA-xmcm-4qr4-5mmq",
"modified": "2022-05-17T01:40:41Z",
"published": "2022-05-17T01:40:41Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2012-5100"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/72138"
},
{
"type": "WEB",
"url": "http://archives.neohapsis.com/archives/bugtraq/2012-01/0028.html"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/51286"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-XMCX-3XP5-5G3C
Vulnerability from github – Published: 2022-05-13 01:11 – Updated: 2022-05-13 01:11NVIDIA GeForce Experience 3.x before GFE 3.1.0.52 contains a vulnerability in NVIDIA Web Helper.exe where a local web API endpoint, /VisualOPS/v.1.0./, lacks proper access control and parameter validation, allowing for information disclosure via a directory traversal attack.
{
"affected": [],
"aliases": [
"CVE-2016-8827"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2016-12-16T21:59:00Z",
"severity": "MODERATE"
},
"details": "NVIDIA GeForce Experience 3.x before GFE 3.1.0.52 contains a vulnerability in NVIDIA Web Helper.exe where a local web API endpoint, /VisualOPS/v.1.0./, lacks proper access control and parameter validation, allowing for information disclosure via a directory traversal attack.",
"id": "GHSA-xmcx-3xp5-5g3c",
"modified": "2022-05-13T01:11:43Z",
"published": "2022-05-13T01:11:43Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2016-8827"
},
{
"type": "WEB",
"url": "https://nvidia.custhelp.com/app/answers/detail/a_id/5033"
},
{
"type": "WEB",
"url": "https://nvidia.custhelp.com/app/answers/detail/a_id/5155"
},
{
"type": "WEB",
"url": "http://nvidia.custhelp.com/app/answers/detail/a_id/4279"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/94964"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-XMFX-VPR2-GPQW
Vulnerability from github – Published: 2022-05-01 18:43 – Updated: 2022-05-01 18:43Incomplete blacklist vulnerability in main.php in phPay 2.02.01 on Windows allows remote attackers to conduct directory traversal attacks and include and execute arbitrary local files via a ..\ (dot dot backslash) in the config parameter.
{
"affected": [],
"aliases": [
"CVE-2007-6471"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2007-12-20T00:46:00Z",
"severity": "MODERATE"
},
"details": "Incomplete blacklist vulnerability in main.php in phPay 2.02.01 on Windows allows remote attackers to conduct directory traversal attacks and include and execute arbitrary local files via a ..\\ (dot dot backslash) in the config parameter.",
"id": "GHSA-xmfx-vpr2-gpqw",
"modified": "2022-05-01T18:43:16Z",
"published": "2022-05-01T18:43:16Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2007-6471"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/39063"
},
{
"type": "WEB",
"url": "http://secunia.com/advisories/28111"
},
{
"type": "WEB",
"url": "http://securityreason.com/securityalert/3466"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/archive/1/485149/100/0/threaded"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/26881"
},
{
"type": "WEB",
"url": "http://www.vupen.com/english/advisories/2007/4231"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-XMGJ-5FH3-XJMM
Vulnerability from github – Published: 2021-12-17 19:59 – Updated: 2021-12-17 19:34Impact
Users who deployed message bus with diagnostics features enabled (default off) were vulnerable to a path traversal bug, which could lead to disclosure of secret information on a machine if an unintended user were to gain access to the diagnostic route. The impact is also greater if there is no proxy for your web application as the number of steps up the directories is not bounded. For deployments which uses a proxy, the impact varies. For example, If a request goes through a proxy like Nginx with merge_slashes enabled, the number of steps up the directories that can be read is limited to 3 levels.
Patches
Patched in 3.3.7.
Workarounds
Disable MessageBus::Diagnostics in production like environments.
{
"affected": [
{
"package": {
"ecosystem": "RubyGems",
"name": "message_bus"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.3.7"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2021-43840"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2021-12-17T19:34:45Z",
"nvd_published_at": "2021-12-17T19:15:00Z",
"severity": "MODERATE"
},
"details": "### Impact\n\nUsers who deployed message bus with diagnostics features enabled (default off) were vulnerable to a path traversal bug, which could lead to disclosure of secret information on a machine if an unintended user were to gain access to the diagnostic route. The impact is also greater if there is no proxy for your web application as the number of steps up the directories is not bounded. For deployments which uses a proxy, the impact varies. For example, If a request goes through a proxy like Nginx with `merge_slashes` enabled, the number of steps up the directories that can be read is limited to 3 levels. \n\n### Patches\n\nPatched in 3.3.7.\n\n### Workarounds\n\nDisable MessageBus::Diagnostics in production like environments. \n",
"id": "GHSA-xmgj-5fh3-xjmm",
"modified": "2021-12-17T19:34:45Z",
"published": "2021-12-17T19:59:13Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/discourse/message_bus/security/advisories/GHSA-xmgj-5fh3-xjmm"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-43840"
},
{
"type": "WEB",
"url": "https://github.com/discourse/message_bus/commit/9b6deee01ed474c7e9b5ff65a06bb0447b4db2ba"
},
{
"type": "PACKAGE",
"url": "https://github.com/discourse/message_bus"
},
{
"type": "WEB",
"url": "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/message_bus/CVE-2021-43840.yml"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
],
"summary": "Path traversal when MessageBus::Diagnostics is enabled"
}
GHSA-XMHF-4P4X-FX7C
Vulnerability from github – Published: 2023-05-18 03:30 – Updated: 2023-05-18 03:30Multiple vulnerabilities in the web-based management interface of Cisco Identity Services Engine (ISE) could allow an authenticated, remote attacker to download arbitrary files from the filesystem of an affected device. These vulnerabilities are due to insufficient input validation. An attacker could exploit these vulnerabilities by sending crafted HTTP requests to an affected device. A successful exploit could allow the attacker to download arbitrary files from the underlying filesystem of the affected device.
{
"affected": [],
"aliases": [
"CVE-2023-20087"
],
"database_specific": {
"cwe_ids": [
"CWE-22",
"CWE-37"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-05-18T03:15:09Z",
"severity": "MODERATE"
},
"details": "Multiple vulnerabilities in the web-based management interface of Cisco Identity Services Engine (ISE) could allow an authenticated, remote attacker to download arbitrary files from the filesystem of an affected device.\n These vulnerabilities are due to insufficient input validation. An attacker could exploit these vulnerabilities by sending crafted HTTP requests to an affected device. A successful exploit could allow the attacker to download arbitrary files from the underlying filesystem of the affected device.\n ",
"id": "GHSA-xmhf-4p4x-fx7c",
"modified": "2023-05-18T03:30:20Z",
"published": "2023-05-18T03:30:20Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-20087"
},
{
"type": "WEB",
"url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-file-dwnld-Srcdnkd2"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
Mitigation MIT-5.1
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 validating filenames, use stringent allowlists that limit the character set to be used. If feasible, only allow a single "." character in the filename to avoid weaknesses such as CWE-23, and exclude directory separators such as "/" to avoid CWE-36. Use a list of allowable file extensions, which will help to avoid CWE-434.
- Do not rely exclusively on a filtering mechanism that removes potentially dangerous characters. This is equivalent to a denylist, which may be incomplete (CWE-184). For example, filtering "/" is insufficient protection if the filesystem also supports the use of "\" as a directory separator. Another possible error could occur when the filtering is applied in a way that still produces dangerous data (CWE-182). For example, if "../" sequences are removed from the ".../...//" string in a sequential fashion, two instances of "../" would be removed from the original string, but the remaining characters would still form the "../" string.
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-20.1
Strategy: Input Validation
- Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
- Use a built-in path canonicalization function (such as realpath() in C) that produces the canonical version of the pathname, which effectively removes ".." sequences and symbolic links (CWE-23, CWE-59). This includes:
- realpath() in C
- getCanonicalPath() in Java
- GetFullPath() in ASP.NET
- realpath() or abs_path() in Perl
- realpath() in PHP
Mitigation MIT-4
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 [REF-1482].
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-21.1
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.
- For example, ID 1 could map to "inbox.txt" and ID 2 could map to "profile.txt". Features such as the ESAPI AccessReferenceMap [REF-185] provide this capability.
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 MIT-34
Strategy: Attack Surface Reduction
- Store library, include, and utility files outside of the web document root, if possible. Otherwise, store them in a separate directory and use the web server's access control capabilities to prevent attackers from directly requesting them. One common practice is to define a fixed constant in each calling program, then check for the existence of the constant in the library/include file; if the constant does not exist, then the file was directly requested, and it can exit immediately.
- This significantly reduces the chance of an attacker being able to bypass any protection mechanisms that are in the base program but not in the include files. It will also reduce the attack surface.
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 path traversal, error messages which disclose path information can help attackers craft the appropriate attack strings to move through the file system hierarchy.
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-126: Path Traversal
An adversary uses path manipulation methods to exploit insufficient input validation of a target to obtain access to data that should be not be retrievable by ordinary well-formed requests. A typical variety of this attack involves specifying a path to a desired file together with dot-dot-slash characters, resulting in the file access API or function traversing out of the intended directory structure and into the root file system. By replacing or modifying the expected path information the access function or API retrieves the file desired by the attacker. These attacks either involve the attacker providing a complete path to a targeted file or using control characters (e.g. path separators (/ or \) and/or dots (.)) to reach desired directories or files.
CAPEC-64: Using Slashes and URL Encoding Combined to Bypass Validation Logic
This attack targets the encoding of the URL combined with the encoding of the slash characters. An attacker can take advantage of the multiple ways of encoding a URL and abuse the interpretation of the URL. A URL may contain special character that need special syntax handling in order to be interpreted. Special characters are represented using a percentage character followed by two digits representing the octet code of the original character (%HEX-CODE). For instance US-ASCII space character would be represented with %20. This is often referred as escaped ending or percent-encoding. Since the server decodes the URL from the requests, it may restrict the access to some URL paths by validating and filtering out the URL requests it received. An attacker will try to craft an URL with a sequence of special characters which once interpreted by the server will be equivalent to a forbidden URL. It can be difficult to protect against this attack since the URL can contain other format of encoding such as UTF-8 encoding, Unicode-encoding, etc.
CAPEC-76: Manipulating Web Input to File System Calls
An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.
CAPEC-78: Using Escaped Slashes in Alternate Encoding
This attack targets the use of the backslash in alternate encoding. An adversary can provide a backslash as a leading character and causes a parser to believe that the next character is special. This is called an escape. By using that trick, the adversary tries to exploit alternate ways to encode the same character which leads to filter problems and opens avenues to attack.
CAPEC-79: Using Slashes in Alternate Encoding
This attack targets the encoding of the Slash characters. An adversary would try to exploit common filtering problems related to the use of the slashes characters to gain access to resources on the target host. Directory-driven systems, such as file systems and databases, typically use the slash character to indicate traversal between directories or other container components. For murky historical reasons, PCs (and, as a result, Microsoft OSs) choose to use a backslash, whereas the UNIX world typically makes use of the forward slash. The schizophrenic result is that many MS-based systems are required to understand both forms of the slash. This gives the adversary many opportunities to discover and abuse a number of common filtering problems. The goal of this pattern is to discover server software that only applies filters to one version, but not the other.