CyberSecBulletin
CVE-2023-4458NVD status: Analyzed

Red Hat Enterprise Linux 6: Out-of-bounds Read

CVE-2023-4458 is a high-severity out-of-bounds read vulnerability in Red Hat Enterprise Linux 6 from Red Hat, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.84% chance of exploitation within 30 days, higher than 59% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux Kernel to 5.15.131 or 6.1.52 or 6.4.15 or 6.5.2, whichever matches your release line, or a later version.
  2. Read the advisory on access.redhat.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Red HatRed Hat Enterprise Linux 6Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 7Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9Not specified in the recordNot stated
LinuxLinux Kernelbefore 5.15.131; 5.16 up to, but not including, 6.1.52; 6.2 up to, but not including, 6.4.15; 6.5 up to, but not including, 6.5.25.15.131, 6.1.52, 6.4.15, 6.5.2

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
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
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
NoneAvailability is not affected.

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

Scoring systemScoreSeverityScored by
CVSS 3.14.0MediumCNA (puiterwijk.org)
CVSS 3.17.5HighNVD

Official description

A flaw was found within the parsing of extended attributes in the kernel ksmbd module. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated buffer. An attacker can leverage this to disclose sensitive information on affected installations of Linux. Only systems with ksmbd enabled are vulnerable to this CVE.

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

Third-party and government advisories

Other vulnerabilities in Red Hat Enterprise Linux 6

All Red Hat Enterprise Linux 6 vulnerabilities

Recent Out-of-bounds Read vulnerabilities

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