phpseclib: Interpretation Conflict
CVE-2023-52892 is a high-severity interpretation conflict vulnerability in phpseclib, 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. The record lists versions 1.0.22, 2.0.46, 3.0.33 as the first without the flaw, so updating phpseclib to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.38% 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
- Update phpseclib to 1.0.22 or 2.0.46 or 3.0.33, whichever matches your release line, or a later version.
- 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 |
|---|---|---|---|
| Phpseclib | phpseclib | before 1.0.22; 2.0 up to, but not including, 2.0.46; 3.0 up to, but not including, 3.0.33 | 1.0.22, 2.0.46, 3.0.33 |
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 CISA (ADP).
Official description
In phpseclib before 1.0.22, 2.x before 2.0.46, and 3.x before 3.0.33, some characters in Subject Alternative Name fields in TLS certificates are incorrectly allowed to have a special meaning in regular expressions (such as a + wildcard), leading to name confusion in X.509 certificate host verification.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Interpretation Conflict
Product A handles inputs or steps differently than Product B, which causes A to perform incorrect actions based on its perception of B's state.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Technical write-ups (may include proof of concept)
- github.com/phpseclib/phpseclib/issues/1943Exploit, Issue Tracking
Other references
- github.com/x509-name-testing/name_testing_artifactsNot Applicable
Other vulnerabilities in phpseclib
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
Recent Interpretation Conflict vulnerabilities
- 9.1 Critical severity
- 7.5 High severity
- 8.8 High severity
- 9.8 Critical severity
- 8.1 High severity
- 7.3 High severity
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