CVE-2024-8158
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.38%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 4.0
- 8.8 HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.38% probability · 31th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-639
- Affected
- 9front/lib9p
- Source
- 1d66c9f9-fff2-411a-aa19-ca6312fa25e9
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.