CVE-2024-8158

User impersonation for lib9p based 9p fileservers

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.

Remediation

Solution:

  • Update 9front to at least commit 9645ae07eb66a59015e3e118d0024790c37400da and follow these update instructions: 1. Make and install the now patched version of lib9p. 2. Make and install the new patched version of hjfs. 3. Make and install the kernel to include the patched hjfs within the kernel's paqfs.

Category

8.8
CVSS
Severity: High
CVSS 4.0 •
CVSS 3.1 •
EPSS 0.07%
Affected: 9front 9front
Published at:
Updated at:

References

Link Tags
https://git.9front.org/plan9front/plan9front/07aa9bfeef55ca987d411115adcfbbd4390ecf34/commit.html patch

Frequently Asked Questions

What is the severity of CVE-2024-8158?
CVE-2024-8158 has been scored as a high severity vulnerability.
How to fix CVE-2024-8158?
To fix CVE-2024-8158: Update 9front to at least commit 9645ae07eb66a59015e3e118d0024790c37400da and follow these update instructions: 1. Make and install the now patched version of lib9p. 2. Make and install the new patched version of hjfs. 3. Make and install the kernel to include the patched hjfs within the kernel's paqfs.
Is CVE-2024-8158 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2024-8158 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2024-8158?
CVE-2024-8158 affects 9front 9front.
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