copyparty: Improper Limitation of a Pathname to a Restricted Directory
CVE-2023-37474 is a high-severity improper limitation of a pathname to a restricted directory vulnerability in copyparty from 9001, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected copyparty versions: < 1.8.2. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 44.9% chance of exploitation within 30 days, which is in the top 1.2% of all scored CVEs.
EPSS places it among the vulnerabilities most likely to be exploited soon.
What to do
- Update copyparty to 1.8.2 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 |
|---|---|---|---|
| 9001 | copyparty | < 1.8.2 | Not stated |
| Copyparty Project | copyparty | before 1.8.2 | 1.8.2 |
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
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 3.0 | 7.5 | High | CNA (github.com) |
Official description
Copyparty is a portable file server. Versions prior to 1.8.2 are subject to a path traversal vulnerability detected in the `.cpr` subfolder. The Path Traversal attack technique allows an attacker access to files, directories, and commands that reside outside the web document root directory. This issue has been addressed in commit `043e3c7d` which has been included in release 1.8.2. Users are advised to upgrade. There are no known workarounds for this 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: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- github.com/9001/copyparty/security/advisories/GHSA-pxfv-7rr3-2qjgExploit, Third Party Advisory
Patches and release notes
Other vulnerabilities in copyparty
- 7.5 High severity
- 7.8 High severity
- 7.5 High severity
Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.5 High severity
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