Attacker Value
Unknown
(0 users assessed)
Exploitability
Unknown
(0 users assessed)
User Interaction
None
Privileges Required
High
Attack Vector
Local
0

CVE-2024-46695

Disclosure Date: September 13, 2024 •
CVE-2024-46695 CVSS v3 Base Score: 4.4
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

In the Linux kernel, the following vulnerability has been resolved:

selinux,smack: don’t bypass permissions check in inode_setsecctx hook

Marek Gresko reports that the root user on an NFS client is able to
change the security labels on files on an NFS filesystem that is
exported with root squashing enabled.

The end of the kerneldoc comment for __vfs_setxattr_noperm() states:

  • This function requires the caller to lock the inode’s i_mutex before it
  • is executed. It also assumes that the caller will make the appropriate
  • permission checks.

nfsd_setattr() does do permissions checking via fh_verify() and
nfsd_permission(), but those don’t do all the same permissions checks
that are done by security_inode_setxattr() and its related LSM hooks do.

Since nfsd_setattr() is the only consumer of security_inode_setsecctx(),
simplest solution appears to be to replace the call to
__vfs_setxattr_noperm() with a call to __vfs_setxattr_locked(). This
fixes the above issue and has the added benefit of causing nfsd to
recall conflicting delegations on a file when a client tries to change
its security label.

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CVSS V3 Severity and Metrics
Base Score:
4.4 Medium
Impact Score:
3.6
Exploitability Score:
0.8
Vector:
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
Attack Vector (AV):
Local
Attack Complexity (AC):
Low
Privileges Required (PR):
High
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
None
Integrity (I):
High
Availability (A):
None

General Information

Offensive Application
Unknown
Utility Class
Unknown
Ports
Unknown
OS
Unknown
Vulnerable Versions
Linux 2dbc4b7bac60
Linux not down converted
Prerequisites
Unknown
Discovered By
Unknown
PoC Author
Unknown
Metasploit Module
Unknown
Reporter
Unknown

Vendors

  • linux

Products

  • linux kernel,
  • linux kernel 6.11
Technical Analysis