CyberSecBulletin
CVE-2024-56606NVD status: Modified

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2024-56606 is a high-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 7.8 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 71b22837a5e55ac27d6a14b9cdf2326587405c4f, 1dc1e1db927056cb323296e2294a855cd003dfe7, 132e615bb1d7cdec2d3cfbdec2efa630e923fd21 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 0.25% 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 71b22837a5e55ac27d6a14b9cdf2326587405c4f or 1dc1e1db927056cb323296e2294a855cd003dfe7 or 132e615bb1d7cdec2d3cfbdec2efa630e923fd21 or a6cf750b737374454a4e03a5ed449a3eb0c96414, whichever matches your release line, or a later version.
  2. Update SIMATIC S7-1500 CPU 1518-4 PN/DP MFP to V3.1.5 or a later version.
  3. Update SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP to V3.1.5 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxb013840810c221f2b0cf641d01531526052dc1fb up to, but not including, 71b22837a5e55ac27d6a14b9cdf2326587405c4f; b013840810c221f2b0cf641d01531526052dc1fb up to, but not including, 1dc1e1db927056cb323296e2294a855cd003dfe7; b013840810c221f2b0cf641d01531526052dc1fb up to, but not including, 132e615bb1d7cdec2d3cfbdec2efa630e923fd21; b013840810c221f2b0cf641d01531526052dc1fb up to, but not including, a6cf750b737374454a4e03a5ed449a3eb0c96414; b013840810c221f2b0cf641d01531526052dc1fb up to, but not including, 157f08db94123e2ba56877dd0ac88908b13a5dd0; b013840810c221f2b0cf641d01531526052dc1fb up to, but not including, fd09880b16d33aa5a7420578e01cd79148fa9829; b013840810c221f2b0cf641d01531526052dc1fb up to, but not including, 46f2a11cb82b657fd15bab1c47821b635e03838b; 3.1471b22837a5e55ac27d6a14b9cdf2326587405c4f, 1dc1e1db927056cb323296e2294a855cd003dfe7, 132e615bb1d7cdec2d3cfbdec2efa630e923fd21, a6cf750b737374454a4e03a5ed449a3eb0c96414, 157f08db94123e2ba56877dd0ac88908b13a5dd0, fd09880b16d33aa5a7420578e01cd79148fa9829
SiemensSIMATIC S7-1500 CPU 1518-4 PN/DP MFPV3.1.0 up to, but not including, V3.1.5V3.1.5
SiemensSIMATIC S7-1500 CPU 1518F-4 PN/DP MFPV3.1.0 up to, but not including, V3.1.5V3.1.5
SiemensSIPLUS S7-1500 CPU 1518-4 PN/DP MFPV3.1.0 up to, but not including, V3.1.5V3.1.5
SiemensRUGGEDCOM RST2428Pbefore V3.2V3.2
SiemensSCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 familybefore V3.2V3.2
SiemensSCALANCE XCM-/XRM-/XCH-/XRH-300 familybefore V3.2V3.2
LinuxLinux Kernelbefore 5.4.287; 5.5 up to, but not including, 5.10.231; 5.11 up to, but not including, 5.15.174; 5.16 up to, but not including, 6.1.120; 6.2 up to, but not including, 6.6.66; 6.7 up to, but not including, 6.12.55.4.287, 5.10.231, 5.15.174, 6.1.120, 6.6.66, 6.12.5

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
LowNo special conditions are needed; the attack works reliably.
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:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.8HighCNA
CVSS 3.17.8HighNVD
CVSS 3.17.8HighCISA (ADP)

Official description

In the Linux kernel, the following vulnerability has been resolved: af_packet: avoid erroring out after sock_init_data() in packet_create() After sock_init_data() the allocated sk object is attached to the provided sock object. On error, packet_create() frees the sk object leaving the dangling pointer in the sock object on return. Some other code may try to use this pointer and cause use-after-free.

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: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Use After Free vulnerabilities

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