CVE-2024-8158
User impersonation for lib9p based 9p fileservers
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
User impersonation for lib9p based 9p fileservers
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.
- Record
CVE-2024-8158- CVSS 4.0
- 8.8 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/AU:N/V:C/RE:L/U:Red - Weakness
- CWE-639
- Updated
- 2026-11-02
EUVDEUVD-2024-48983
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.
- Record
EUVD-2024-48983- CVSS 4.0
- 8.8 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/AU:N/V:C/RE:L/U:Red - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-pm23-3px3-qrh7
A bug in the 9p authentication implementation within lib9p allows an attacker with an existing...
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.
- Record
GHSA-pm23-3px3-qrh7- CVSS 4.0
- 8.8 High
CVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:N/R:X/V:C/RE:L/U:Red - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-639
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2024-8158- CVSS 4.0
- 8.8 High
CVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:N/R:X/V:C/RE:L/U:Red - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-639
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2024-8158 is a high vulnerability (CVSS 8.8) in 9front, published August 25, 2024. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.38%, the 31st percentile. No source names a fixed version.