CyberSecBulletin
CVE-2024-27397NVD status: Modified

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2024-27397 is a high-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 7.0 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions f8dfda798650241c1692058713ca4fef8e429061, eaf1a29ea5d7dba8e84e9e9f3b3f47d0cd540bfe, 7b17de2a71e56c10335b565cc7ad238e6d984379 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.26% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to f8dfda798650241c1692058713ca4fef8e429061 or eaf1a29ea5d7dba8e84e9e9f3b3f47d0cd540bfe or 7b17de2a71e56c10335b565cc7ad238e6d984379 or 0d40e8cb1d1f56a994cdd2e015af622fdca9ed4d, whichever matches your release line, or a later version.
  2. Update SIMATIC S7-1500 TM MFP - GNU/Linux subsystem to V1.1.1 or a later version.
  3. Update Linux Kernel to 4.19.320 or 5.4.282 or 5.10.224 or 5.15.165, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxc3e1b005ed1cc068fc9d454a6e745830d55d251d up to, but not including, f8dfda798650241c1692058713ca4fef8e429061; c3e1b005ed1cc068fc9d454a6e745830d55d251d up to, but not including, eaf1a29ea5d7dba8e84e9e9f3b3f47d0cd540bfe; c3e1b005ed1cc068fc9d454a6e745830d55d251d up to, but not including, 7b17de2a71e56c10335b565cc7ad238e6d984379; c3e1b005ed1cc068fc9d454a6e745830d55d251d up to, but not including, 0d40e8cb1d1f56a994cdd2e015af622fdca9ed4d; c3e1b005ed1cc068fc9d454a6e745830d55d251d up to, but not including, b45176b869673417ace338b87cf9cdb66e2eeb01; c3e1b005ed1cc068fc9d454a6e745830d55d251d up to, but not including, 7fa2e2960fff8322ce2ded57b5f8e9cbc450b967; c3e1b005ed1cc068fc9d454a6e745830d55d251d up to, but not including, 383182db8d58c4237772ba0764cded4938a235c3; c3e1b005ed1cc068fc9d454a6e745830d55d251d up to, but not including, 7395dfacfff65e9938ac0889dafa1ab01e987d15; and 1 more rangesf8dfda798650241c1692058713ca4fef8e429061, eaf1a29ea5d7dba8e84e9e9f3b3f47d0cd540bfe, 7b17de2a71e56c10335b565cc7ad238e6d984379, 0d40e8cb1d1f56a994cdd2e015af622fdca9ed4d, b45176b869673417ace338b87cf9cdb66e2eeb01, 7fa2e2960fff8322ce2ded57b5f8e9cbc450b967
SiemensSIMATIC S7-1500 TM MFP - GNU/Linux subsystembefore V1.1.1V1.1.1
LinuxLinux Kernel4.1 up to, but not including, 4.19.320; 4.20 up to, but not including, 5.4.282; 5.5 up to, but not including, 5.10.224; 5.11 up to, but not including, 5.15.165; 5.16 up to, but not including, 6.1.97; 6.2 up to, but not including, 6.6.84; 6.7 up to, but not including, 6.7.5; 6.84.19.320, 5.4.282, 5.10.224, 5.15.165, 6.1.97, 6.6.84

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.8HighCNA
CVSS 3.17.0HighNVD

Official description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: use timestamp to check for set element timeout Add a timestamp field at the beginning of the transaction, store it in the nftables per-netns area. Update set backend .insert, .deactivate and sync gc path to use the timestamp, this avoids that an element expires while control plane transaction is still unfinished. .lookup and .update, which are used from packet path, still use the current time to check if the element has expired. And .get path and dump also since this runs lockless under rcu read size lock. Then, there is async gc which also needs to check the current time since it runs asynchronously from a workqueue.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

How developers prevent this class of flaw

  • Choose a language that provides automatic memory management.
  • When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.

More Use After Free vulnerabilities (CWE-416)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Use After Free vulnerabilities

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