CyberSecBulletin
CVE-2023-5249NVD status: Modified

Bifrost GPU Kernel Driver: Use After Free

CVE-2023-5249 is a high-severity use after free vulnerability in Bifrost GPU Kernel Driver from Arm, 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. Affected Bifrost GPU Kernel Driver versions: r35p0 through r40p0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.15% 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. Check which version of Bifrost GPU Kernel Driver you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on developer.arm.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
ArmBifrost GPU Kernel Driverr35p0 through r40p0Not stated
ArmValhall GPU Kernel Driverr35p0 through r40p0Not stated

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 3.17.0HighNVD
CVSS 3.17.0HighCISA (ADP)

Official description

Use After Free vulnerability in Arm Ltd Bifrost GPU Kernel Driver, Arm Ltd Valhall GPU Kernel Driver allows a local non-privileged user to make improper memory processing operations to exploit a software race condition. If the system’s memory is carefully prepared by the user, then this in turn cause a use-after-free.This issue affects Bifrost GPU Kernel Driver: from r35p0 through r40p0; Valhall GPU Kernel Driver: from r35p0 through r40p0.

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

Other vulnerabilities in Bifrost GPU Kernel Driver

All Bifrost GPU Kernel Driver vulnerabilities

Recent Use After Free vulnerabilities

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