security-advisories: Use of Incorrectly-Resolved Name or Reference
CVE-2023-28643 is a high-severity use of incorrectly-resolved name or reference vulnerability in security-advisories from Nextcloud, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected security-advisories versions: < 24.0.9; >= 25.0.0, < 25.0.3. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.79% chance of exploitation within 30 days, higher than 57% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Nextcloud Server to 24.0.9 or 25.0.3, whichever matches your release line, or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Nextcloud | security-advisories | < 24.0.9; >= 25.0.0, < 25.0.3 | Not stated |
| Nextcloud | Nextcloud Server | 24.0.0 up to, but not including, 24.0.9; 25.0.0 up to, but not including, 25.0.3 | 24.0.9, 25.0.3 |
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
- LowA basic user account is enough.
- 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:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 5.5 | Medium | CNA (github.com) |
| CVSS 3.1 | 8.8 | High | NVD |
Official description
Nextcloud server is an open source home cloud implementation. In affected versions when a recipient receives 2 shares with the same name, while a memory cache is configured, the second share will replace the first one instead of being renamed to `{name} (2)`. It is recommended that the Nextcloud Server is upgraded to 25.0.3 or 24.0.9. Users unable to upgrade should avoid sharing 2 folders with the same name to the same user.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Incorrectly-Resolved Name or Reference
The product uses a name or reference to access a resource, but the name/reference resolves to a resource that is outside of the intended control sphere.
More Use of Incorrectly-Resolved Name or Reference vulnerabilities (CWE-706)
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
- github.com/nextcloud/server/pull/36047Issue Tracking
Technical write-ups (may include proof of concept)
- github.com/nextcloud/server/issues/34015Exploit, Issue Tracking
Other vulnerabilities in security-advisories
- 7.1 High severity
- 8.2 High severity
- 8.8 High severity
- 8.1 High severity
- 8.1 High severity
Recent Use of Incorrectly-Resolved Name or Reference vulnerabilities
- 7.0 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.1 High severity
- 9.8 Critical severity
- 9.8 Critical severity
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