plexus-archiver: Improper Limitation of a Pathname to a Restricted Directory
CVE-2023-37460 is a critical-severity improper limitation of a pathname to a restricted directory vulnerability in plexus-archiver from Codehaus-plexus, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 4.8.0 as the first without the flaw, so updating plexus-archiver to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 2.48% chance of exploitation within 30 days, higher than 85% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update plexus-archiver to 4.8.0 or a later version.
- 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
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Codehaus-plexus | plexus-archiver | < 4.8.0; before 4.8.0 | 4.8.0 |
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
- LowNo special conditions are needed; the attack works reliably.
- 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:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.1 | High | CNA (github.com) |
| CVSS 3.1 | 9.8 | Critical | NVD |
Official description
Plexis Archiver is a collection of Plexus components to create archives or extract archives to a directory with a unified `Archiver`/`UnArchiver` API. Prior to version 4.8.0, using AbstractUnArchiver for extracting an archive might lead to an arbitrary file creation and possibly remote code execution. When extracting an archive with an entry that already exists in the destination directory as a symbolic link whose target does not exist - the `resolveFile()` function will return the symlink's source instead of its target, which will pass the verification that ensures the file will not be extracted outside of the destination directory. Later `Files.newOutputStream()`, that follows symlinks by default, will actually write the entry's content to the symlink's target. Whoever uses plexus archiver to extract an untrusted archive is vulnerable to an arbitrary file creation and possibly remote code execution. Version 4.8.0 contains a patch for this issue.
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: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
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