CyberSecBulletin
CVE-2023-52501NVD status: Analyzed

Linux: Out-of-bounds Read

Published Updated By the CyberSecBulletin desk

CVE-2023-52501 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.1 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 cee5151c5410e868826b8afecfb356f3799ebea3, 344f2f3e61a90f0150c754796ec9a17fcaeec03d, b08a4938229dbb530a35c41b83002a1457c6ff49 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 cee5151c5410e868826b8afecfb356f3799ebea3 or 344f2f3e61a90f0150c754796ec9a17fcaeec03d or b08a4938229dbb530a35c41b83002a1457c6ff49 or 75fc9e99b3a71006720ad1e029db11a4b5c32d4a, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.198 or 5.15.134, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux785888c544e0433f601df18ff98a3215b380b9c3 up to, but not including, cee5151c5410e868826b8afecfb356f3799ebea3; 785888c544e0433f601df18ff98a3215b380b9c3 up to, but not including, 344f2f3e61a90f0150c754796ec9a17fcaeec03d; 785888c544e0433f601df18ff98a3215b380b9c3 up to, but not including, b08a4938229dbb530a35c41b83002a1457c6ff49; 785888c544e0433f601df18ff98a3215b380b9c3 up to, but not including, 75fc9e99b3a71006720ad1e029db11a4b5c32d4a; 785888c544e0433f601df18ff98a3215b380b9c3 up to, but not including, 95a404bd60af6c4d9d8db01ad14fe8957ece31ca; 5.7cee5151c5410e868826b8afecfb356f3799ebea3, 344f2f3e61a90f0150c754796ec9a17fcaeec03d, b08a4938229dbb530a35c41b83002a1457c6ff49, 75fc9e99b3a71006720ad1e029db11a4b5c32d4a, 95a404bd60af6c4d9d8db01ad14fe8957ece31ca
LinuxLinux Kernelbefore 5.10.198; 5.11 up to, but not including, 5.15.134; 5.16 through 6.1.56; 6.2 through 6.5.6; 6.65.10.198, 5.15.134

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
NoneNothing can be modified.
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:N/A:H. Scored by NVD.

Official description

In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Do not attempt to read past "commit" When iterating over the ring buffer while the ring buffer is active, the writer can corrupt the reader. There's barriers to help detect this and handle it, but that code missed the case where the last event was at the very end of the page and has only 4 bytes left. The checks to detect the corruption by the writer to reads needs to see the length of the event. If the length in the first 4 bytes is zero then the length is stored in the second 4 bytes. But if the writer is in the process of updating that code, there's a small window where the length in the first 4 bytes could be zero even though the length is only 4 bytes. That will cause rb_event_length() to read the next 4 bytes which could happen to be off the allocated page. To protect against this, fail immediately if the next event pointer is less than 8 bytes from the end of the commit (last byte of data), as all events must be a minimum of 8 bytes anyway.

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

The underlying weakness: Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that provides appropriate memory abstractions.

More Out-of-bounds Read vulnerabilities (CWE-125)

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 Out-of-bounds Read vulnerabilities

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