reason-jose: Improper Verification of Cryptographic Signature
CVE-2023-23928 is a critical-severity improper verification of cryptographic signature vulnerability in reason-jose from Ulrikstrid, 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. Affected reason-jose versions: < 0.8.2. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.48% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of reason-jose you run against the affected versions below, and install the vendor's latest release.
- 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 |
|---|---|---|---|
| Ulrikstrid | reason-jose | < 0.8.2 | Not stated |
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 | 5.9 | Medium | CNA (github.com) |
| CVSS 3.1 | 9.8 | Critical | NVD |
Official description
reason-jose is a JOSE implementation in ReasonML and OCaml.`Jose.Jws.validate` does not check HS256 signatures. This allows tampering of JWS header and payload data if the service does not perform additional checks. Such tampering could expose applications using reason-jose to authorization bypass. Applications relying on JWS claims assertion to enforce security boundaries may be vulnerable to privilege escalation. This issue has been patched in version 0.8.2.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Verification of Cryptographic Signature
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
More Improper Verification of Cryptographic Signature vulnerabilities (CWE-347)
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
Advisories
- github.com/ulrikstrid/reason-jose/security/advisories/GHSA-7jj9-6qwv-wpm7Third Party Advisory
Patches and release notes
- github.com/ulrikstrid/reason-jose/commit/36cd724db3cbec121757624da49072386bd869e5Third Party Advisory
- github.com/ulrikstrid/reason-jose/releases/tag/v0.8.2Release Notes, Third Party Advisory
Recent Improper Verification of Cryptographic Signature vulnerabilities
- 7.8 High severity
- 9.8 Critical severity
- 7.5 High severity
- 7.6 High severity
- 7.8 High severity
- 7.8 High severity
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