CyberSecBulletin
CVE-2023-53676NVD status: Modified

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2023-53676 is a high-severity out-of-bounds write 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 df349e84c2cb0dd05d98c8e1189c26ab4b116083, 114b44dddea1f8f99576de3c0e6e9059012002fc, 2cbe6a88fbdd6e8aeab358eef61472e2de43d6f6 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 0.33% 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 df349e84c2cb0dd05d98c8e1189c26ab4b116083 or 114b44dddea1f8f99576de3c0e6e9059012002fc or 2cbe6a88fbdd6e8aeab358eef61472e2de43d6f6 or bbe3ff47bf09db8956bc2eeb49d2d514d256ad2a, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 4.14.326 or 4.19.295 or 5.4.257 or 5.10.197, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxe48354ce078c079996f89d715dfa44814b4eba01 up to, but not including, df349e84c2cb0dd05d98c8e1189c26ab4b116083; e48354ce078c079996f89d715dfa44814b4eba01 up to, but not including, 114b44dddea1f8f99576de3c0e6e9059012002fc; e48354ce078c079996f89d715dfa44814b4eba01 up to, but not including, 2cbe6a88fbdd6e8aeab358eef61472e2de43d6f6; e48354ce078c079996f89d715dfa44814b4eba01 up to, but not including, bbe3ff47bf09db8956bc2eeb49d2d514d256ad2a; e48354ce078c079996f89d715dfa44814b4eba01 up to, but not including, 5353df78c22623b42a71d51226d228a8413097e2; e48354ce078c079996f89d715dfa44814b4eba01 up to, but not including, 4738bf8b2d3635c2944b81b2a84d97b8c8b0978d; e48354ce078c079996f89d715dfa44814b4eba01 up to, but not including, 0cac6cbb9908309352a5d30c1876882771d3da50; e48354ce078c079996f89d715dfa44814b4eba01 up to, but not including, 801f287c93ff95582b0a2d2163f12870a2f076d4; and 1 more rangesdf349e84c2cb0dd05d98c8e1189c26ab4b116083, 114b44dddea1f8f99576de3c0e6e9059012002fc, 2cbe6a88fbdd6e8aeab358eef61472e2de43d6f6, bbe3ff47bf09db8956bc2eeb49d2d514d256ad2a, 5353df78c22623b42a71d51226d228a8413097e2, 4738bf8b2d3635c2944b81b2a84d97b8c8b0978d
LinuxLinux Kernel3.1 up to, but not including, 4.14.326; 4.15 up to, but not including, 4.19.295; 4.20 up to, but not including, 5.4.257; 5.5 up to, but not including, 5.10.197; 5.11 up to, but not including, 5.15.133; 5.16 up to, but not including, 6.1.55; 6.2 up to, but not including, 6.5.54.14.326, 4.19.295, 5.4.257, 5.10.197, 5.15.133, 6.1.55

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 3.18.8HighCNA
CVSS 3.17.8HighNVD

Official description

In the Linux kernel, the following vulnerability has been resolved: scsi: target: iscsi: Fix buffer overflow in lio_target_nacl_info_show() The function lio_target_nacl_info_show() uses sprintf() in a loop to print details for every iSCSI connection in a session without checking for the buffer length. With enough iSCSI connections it's possible to overflow the buffer provided by configfs and corrupt the memory. This patch replaces sprintf() with sysfs_emit_at() that checks for buffer boundries.

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

The underlying weakness: Out-of-bounds Write

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

How developers prevent this class of flaw

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Out-of-bounds Write vulnerabilities (CWE-787)

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 Out-of-bounds Write vulnerabilities

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