CyberSecBulletin
CVE-2024-57951NVD status: Modified

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2024-57951 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 95e4f62df23f4df1ce6ef897d44b8e23c260921a, 14984139f1f2768883332965db566ef26db609e7, 15b453db41d36184cf0ccc21e7df624014ab6a1a 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 0.27% 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 95e4f62df23f4df1ce6ef897d44b8e23c260921a or 14984139f1f2768883332965db566ef26db609e7 or 15b453db41d36184cf0ccc21e7df624014ab6a1a or 3d41dbf82e10c44e53ea602398ab002baec27e75, 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 RUGGEDCOM RST2428P to V3.2 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux54d0d83a53508d687fd4a225f8aa1f18559562d0 up to, but not including, 95e4f62df23f4df1ce6ef897d44b8e23c260921a; 7f4c89400d2997939f6971c7981cc780a219e36b up to, but not including, 14984139f1f2768883332965db566ef26db609e7; 6fcbcc6c8e52650749692c7613cbe71bf601670d up to, but not including, 15b453db41d36184cf0ccc21e7df624014ab6a1a; 75b5016ce325f1ef9c63e5398a1064cf8a7a7354 up to, but not including, 3d41dbf82e10c44e53ea602398ab002baec27e75; 53f408cad05bb987af860af22f4151e5a18e6ee8 up to, but not including, a5cbbea145b400e40540c34816d16d36e0374fbc; 5c0930ccaad5a74d74e8b18b648c5eb21ed2fe94 up to, but not including, 38492f6ee883c7b1d33338bf531a62cff69b4b28; 5c0930ccaad5a74d74e8b18b648c5eb21ed2fe94 up to, but not including, 2f8dea1692eef2b7ba6a256246ed82c365fdc686; 9a2fc41acb69dd4e2a58d0c04346c3333c2341fc; and 7 more ranges95e4f62df23f4df1ce6ef897d44b8e23c260921a, 14984139f1f2768883332965db566ef26db609e7, 15b453db41d36184cf0ccc21e7df624014ab6a1a, 3d41dbf82e10c44e53ea602398ab002baec27e75, a5cbbea145b400e40540c34816d16d36e0374fbc, 38492f6ee883c7b1d33338bf531a62cff69b4b28
SiemensSIMATIC S7-1500 TM MFP - GNU/Linux subsystembefore V1.1.1V1.1.1
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 Kernel4.19.302 up to, but not including, 4.20; 5.4.264 up to, but not including, 5.4.290; 5.10.204 up to, but not including, 5.10.234; 5.15.143 up to, but not including, 5.15.177; 6.1.68 up to, but not including, 6.1.127; 6.6.7 up to, but not including, 6.6.74; 6.7 up to, but not including, 6.12.11; 6.134.20, 5.4.290, 5.10.234, 5.15.177, 6.1.127, 6.6.74

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 3.17.8HighNVD
CVSS 3.17.8HighCISA (ADP)

Official description

In the Linux kernel, the following vulnerability has been resolved: hrtimers: Handle CPU state correctly on hotplug Consider a scenario where a CPU transitions from CPUHP_ONLINE to halfway through a CPU hotunplug down to CPUHP_HRTIMERS_PREPARE, and then back to CPUHP_ONLINE: Since hrtimers_prepare_cpu() does not run, cpu_base.hres_active remains set to 1 throughout. However, during a CPU unplug operation, the tick and the clockevents are shut down at CPUHP_AP_TICK_DYING. On return to the online state, for instance CFS incorrectly assumes that the hrtick is already active, and the chance of the clockevent device to transition to oneshot mode is also lost forever for the CPU, unless it goes back to a lower state than CPUHP_HRTIMERS_PREPARE once. This round-trip reveals another issue; cpu_base.online is not set to 1 after the transition, which appears as a WARN_ON_ONCE in enqueue_hrtimer(). Aside of that, the bulk of the per CPU state is not reset either, which means there are dangling pointers in the worst case. Address this by adding a corresponding startup() callback, which resets the stale per CPU state and sets the online flag. [ tglx: Make the new callback unconditionally available, remove the online modification in the prepare() callback and clear the remaining state in the starting callback instead of the prepare callback ]

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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