CVE-2024-8158

User impersonation for lib9p based 9p fileservers

MEDIUM
6.5
CVSS Score
Published: August 25, 2024 at 09:31 PM UTC
Updated: June 17, 2026 at 08:22 AM UTC
2 products affected across 1 vendorLIB9P9FRONT

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.4%
SSVC
No known 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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2024-08-24
Affected range stops below 2024-08-24, so it looks safe — our inference, not a vendor statement
v < 9645ae07eb66a59015e3e118d0024790c37400da

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-639

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