gradle: Improper Limitation of a Pathname to a Restricted Directory
CVE-2023-35947 is a high-severity improper limitation of a pathname to a restricted directory vulnerability in gradle, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected gradle versions: < 7.6.1; >= 8.0, < 8.2. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.53% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of gradle you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 6.9 | Medium | CNA (github.com) |
| CVSS 3.1 | 8.1 | High | NVD |
Official description
Gradle is a build tool with a focus on build automation and support for multi-language development. In affected versions when unpacking Tar archives, Gradle did not check that files could be written outside of the unpack location. This could lead to important files being overwritten anywhere the Gradle process has write permissions. For a build reading Tar entries from a Tar archive, this issue could allow Gradle to disclose information from sensitive files through an arbitrary file read. To exploit this behavior, an attacker needs to either control the source of an archive already used by the build or modify the build to interact with a malicious archive. It is unlikely that this would go unnoticed. A fix has been released in Gradle 7.6.2 and 8.2 to protect against this vulnerability. Starting from these versions, Gradle will refuse to handle Tar archives which contain path traversal elements in a Tar entry name. Users are advised to upgrade. There are no known workarounds for this vulnerability. ### Impact This is a path traversal vulnerability when Gradle deals with Tar archives, often referenced as TarSlip, a variant of ZipSlip. * When unpacking Tar archives, Gradle did not check that files could be written outside of the unpack location. This could lead to important files being overwritten anywhere the Gradle process has write permissions. * For a build reading Tar entries from a Tar archive, this issue could allow Gradle to disclose information from sensitive files through an arbitrary file read. To exploit this behavior, an attacker needs to either control the source of an archive already used by the build or modify the build to interact with a malicious archive. It is unlikely that this would go unnoticed. Gradle uses Tar archives for its [Build Cache](https://docs.gradle.org/current/userguide/build_cache.html). These archives are safe when created by Gradle. But if an attacker had control of a remote build cache server, they could inject malicious build cache entries that leverage this vulnerability. This attack vector could also be exploited if a man-in-the-middle can be performed between the remote cache and the build. ### Patches A fix has been released in Gradle 7.6.2 and 8.2 to protect against this vulnerability. Starting from these versions, Gradle will refuse to handle Tar archives which contain path traversal elements in a Tar entry name. It is recommended that users upgrade to a patched version. ### Workarounds There is no workaround. * If your build deals with Tar archives that you do not fully trust, you need to inspect them to confirm they do not attempt to leverage this vulnerability. * If you use the Gradle remote build cache, make sure only trusted parties have write access to it and that connections to the remote cache are properly secured. ### References * [CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')](https://cwe.mitre.org/data/definitions/22.html) * [Gradle Build Cache](https://docs.gradle.org/current/userguide/build_cache.html) * [ZipSlip](https://security.snyk.io/research/zip-slip-vulnerability)
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Limitation of a Pathname to a Restricted Directory
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.
How developers prevent this class of flaw
- 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.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- 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.
More Improper Limitation of a Pathname to a Restricted Directory vulnerabilities (CWE-22)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Third-party and government advisories
- security.netapp.com/advisory/ntap-20230803-0007/Third Party Advisory
Other vulnerabilities in gradle
- 7.4 High severity
- 7.4 High severity
- 8.8 High severity
- 9.8 Critical severity
- 7.5 High severity
Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities
- 7.5 High severity
- 9.8 Critical severity
- 9.1 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.1 High severity
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