What’s Vulnerable › Vulnerabilities
CVE-2024-8158: User impersonation for lib9p based 9p fileservers
- Severity: medium (CVSS 6.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2024-08-25 · updated 2026-06-17
- Weakness: CWE-639
Description
A bug in the 9p authentication implementation within lib9p allows an attacker with an existing valid user within the configured auth server to impersonate any other valid filesystem user. This is due to lib9p not properly verifying that the uname given in the Tauth and Tattach 9p messages matches the client UID returned from the factotum authentication handshake. The only filesystem making use of these functions within the base 9front systems is the experimental hjfs disk filesystem, other disk filesystems (cwfs and gefs) are not affected by this bug. This bug was inherited from Plan 9 and is present in all versions of 9front and is remedied fully in commit 9645ae07eb66a59015e3e118d0024790c37400da.
Affected products
- 9front Lib9P: before 2024-08-24 — fixed in 2024-08-24
How to fix
Upgrade to a fixed version: 9front Lib9P 2024-08-24. Check the vendor advisory for mitigations.
References
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