Red Hat Enterprise Linux 8: Concurrent Execution using Shared Resource with Improper Synchronization
CVE-2023-6546 is a high-severity concurrent execution using shared resource with improper synchronization vulnerability in Red Hat Enterprise Linux 8 from Red Hat, 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. There is no confirmed exploitation so far. EPSS estimates a 0.73% chance of exploitation within 30 days, higher than 55% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux Kernel to 6.5 or a later version.
Affected products and versions
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 system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.0 | High | CNA (redhat.com) |
| CVSS 3.1 | 7.0 | High | NVD |
Official description
A race condition was found in the GSM 0710 tty multiplexor in the Linux kernel. This issue occurs when two threads execute the GSMIOC_SETCONF ioctl on the same tty file descriptor with the gsm line discipline enabled, and can lead to a use-after-free problem on a struct gsm_dlci while restarting the gsm mux. This could allow a local unprivileged user to escalate their privileges on the system.
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).
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- bugzilla.redhat.com/show_bug.cgi?id=2255498Issue Tracking, Third Party Advisory
- github.com/torvalds/linux/commit/3c4f8333b582487a2d1e02171f1465531cde53e3
Third-party and government advisories
- access.redhat.com/security/cve/CVE-2023-6546Third Party Advisory
Other references
- access.redhat.com/errata/RHSA-2024:0930
- access.redhat.com/errata/RHSA-2024:0937
- access.redhat.com/errata/RHSA-2024:1018
- access.redhat.com/errata/RHSA-2024:1019
- access.redhat.com/errata/RHSA-2024:1055
- access.redhat.com/errata/RHSA-2024:1250
- access.redhat.com/errata/RHSA-2024:1253
- access.redhat.com/errata/RHSA-2024:1306
- access.redhat.com/errata/RHSA-2024:1607
- access.redhat.com/errata/RHSA-2024:1612
- access.redhat.com/errata/RHSA-2024:1614
- access.redhat.com/errata/RHSA-2024:2093
- access.redhat.com/errata/RHSA-2024:2394
- access.redhat.com/errata/RHSA-2024:2621
- access.redhat.com/errata/RHSA-2024:2697
Other vulnerabilities in Red Hat Enterprise Linux 8
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.9 High severity
- 7.3 High severity
- 7.5 High severity
Recent Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities
- 8.1 High severity
- 8.1 High severity
- 7.0 High severity
- 8.1 High severity
- 7.0 High severity
- 7.5 High severity
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