CyberSecBulletin
CVE-2023-53622NVD status: Analyzed

Linux: Concurrent Execution using Shared Resource with Improper Synchronization

Published Updated By the CyberSecBulletin desk

CVE-2023-53622 is a high-severity concurrent execution using shared resource with improper synchronization vulnerability in Linux, 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. The record lists versions 7e5bbeb7eb813bb2568e1d5d02587df943272e57, 235a5ae73cea29109a3e06f100493f17857e6a93, b4a7ab57effbed42624842f2ab2a49b177c21a47 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 0.15% 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. Update Linux to 7e5bbeb7eb813bb2568e1d5d02587df943272e57 or 235a5ae73cea29109a3e06f100493f17857e6a93 or b4a7ab57effbed42624842f2ab2a49b177c21a47 or 7c5b2649f6a37d45bfb7abf34c9b71d08677139f, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 4.14.324 or 4.19.293 or 5.4.255 or 5.10.192, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux48c2b613616235d7c97fda5982f50100a6c79166 up to, but not including, 7e5bbeb7eb813bb2568e1d5d02587df943272e57; 48c2b613616235d7c97fda5982f50100a6c79166 up to, but not including, 235a5ae73cea29109a3e06f100493f17857e6a93; 48c2b613616235d7c97fda5982f50100a6c79166 up to, but not including, b4a7ab57effbed42624842f2ab2a49b177c21a47; 48c2b613616235d7c97fda5982f50100a6c79166 up to, but not including, 7c5b2649f6a37d45bfb7abf34c9b71d08677139f; 48c2b613616235d7c97fda5982f50100a6c79166 up to, but not including, 85e888150075cb221270b64bf772341fc6bd11d9; 48c2b613616235d7c97fda5982f50100a6c79166 up to, but not including, a4f71523ed2123d63b431cc0cea4e9f363a0f054; 48c2b613616235d7c97fda5982f50100a6c79166 up to, but not including, 42077d4de49e4d9c773c97c42d5383b4899a8f9d; 48c2b613616235d7c97fda5982f50100a6c79166 up to, but not including, 6fa0a72cbbe45db4ed967a51f9e6f4e3afe61d20; and 1 more ranges7e5bbeb7eb813bb2568e1d5d02587df943272e57, 235a5ae73cea29109a3e06f100493f17857e6a93, b4a7ab57effbed42624842f2ab2a49b177c21a47, 7c5b2649f6a37d45bfb7abf34c9b71d08677139f, 85e888150075cb221270b64bf772341fc6bd11d9, a4f71523ed2123d63b431cc0cea4e9f363a0f054
LinuxLinux Kernel2.6.31 up to, but not including, 4.14.324; 4.15 up to, but not including, 4.19.293; 4.20 up to, but not including, 5.4.255; 5.5 up to, but not including, 5.10.192; 5.11 up to, but not including, 5.15.128; 5.16 up to, but not including, 6.1.47; 6.2 up to, but not including, 6.4.124.14.324, 4.19.293, 5.4.255, 5.10.192, 5.15.128, 6.1.47

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.

Official description

In the Linux kernel, the following vulnerability has been resolved: gfs2: Fix possible data races in gfs2_show_options() Some fields such as gt_logd_secs of the struct gfs2_tune are accessed without holding the lock gt_spin in gfs2_show_options(): val = sdp->sd_tune.gt_logd_secs; if (val != 30) seq_printf(s, ",commit=%d", val); And thus can cause data races when gfs2_show_options() and other functions such as gfs2_reconfigure() are concurrently executed: spin_lock(&gt->gt_spin); gt->gt_logd_secs = newargs->ar_commit; To fix these possible data races, the lock sdp->sd_tune.gt_spin is acquired before accessing the fields of gfs2_tune and released after these accesses. Further changes by Andreas: - Don't hold the spin lock over the seq_printf operations.

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

The underlying weakness: Concurrent Execution using Shared Resource with Improper Synchronization

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

How developers prevent this class of flaw

  • In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
  • Use thread-safe capabilities such as the data access abstraction in Spring.
  • Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring. Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).

More Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities (CWE-362)

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 Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities

Spotted an error? Tell us.