Repox: Improper Restriction of XML External Entity Reference
CVE-2023-6721 is a high-severity improper restriction of XML external entity reference vulnerability in Repox, 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 Repox versions: 2.3.7 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.6% 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 Repox you run against the affected versions below, and install the vendor's latest release.
- 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
- 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
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.3 | High | CNA (incibe.es) |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
An XEE vulnerability has been found in Repox, which allows a remote attacker to interfere with the application's XML data processing in the fileupload function, resulting in interaction between the attacker and the server's file system.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Restriction of XML External Entity Reference
The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.
How developers prevent this class of flaw
- Many XML parsers and validators can be configured to disable external entity expansion.
More Improper Restriction of XML External Entity Reference vulnerabilities (CWE-611)
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- incibe.es/en/incibe-cert/notices/aviso/multiple-vulnerabilities-repoxThird Party Advisory
Other vulnerabilities in Repox
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
Recent Improper Restriction of XML External Entity Reference vulnerabilities
- 7.1 High severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
- 7.5 High severity
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