Linux Kernel: Out-of-bounds Write
CVE-2023-6931 is a high-severity out-of-bounds write vulnerability in Linux Kernel from 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 4.19.302, 5.4.264, 5.10.204 as the first without the flaw, so updating Linux Kernel to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.2% chance of exploitation within 30 days, higher than 69% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux Kernel to 4.19.302 or 5.4.264 or 5.10.204 or 5.15.143, whichever matches your release line, or a later version.
- Update SIMATIC S7-1500 CPU 1518-4 PN/DP MFP to V3.1.5 or a later version.
- Update SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP to V3.1.5 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux Kernel | 4.3.0 up to, but not including, 4.19.302; 4.20.0 up to, but not including, 5.4.264; 5.5.0 up to, but not including, 5.10.204; 5.11.0 up to, but not including, 5.15.143; 5.16.0 up to, but not including, 6.1.68; 6.2.0 up to, but not including, 6.6.7 | 4.19.302, 5.4.264, 5.10.204, 5.15.143, 6.1.68, 6.6.7 |
| Siemens | RUGGEDCOM RST2428P | Not specified in the record | Not stated |
| Siemens | SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family | Not specified in the record | Not stated |
| Siemens | SCALANCE XCM-/XRM-/XCH-/XRH-300 family | Not specified in the record | Not stated |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP | V3.1.0 up to, but not including, V3.1.5 | V3.1.5 |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP | V3.1.0 up to, but not including, V3.1.5 | V3.1.5 |
| Siemens | SIMATIC S7-1500 TM MFP - GNU/Linux subsystem | before V1.1; before V1.1.1 | V1.1, V1.1.1 |
| Siemens | SIPLUS S7-1500 CPU 1518-4 PN/DP MFP | V3.1.0 up to, but not including, V3.1.5 | V3.1.5 |
| Debian | Debian Linux | 10.0 | Not stated |
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 | 7.8 | High | CNA (google.com) |
| CVSS 3.1 | 7.0 | High | NVD |
Official description
A heap out-of-bounds write vulnerability in the Linux kernel's Performance Events system component can be exploited to achieve local privilege escalation. A perf_event's read_size can overflow, leading to an heap out-of-bounds increment or write in perf_read_group(). We recommend upgrading past commit 382c27f4ed28f803b1f1473ac2d8db0afc795a1b.
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.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Third-party and government advisories
- lists.debian.org/debian-lts-announce/2024/01/msg00004.htmlMailing List, Third Party Advisory
- lists.debian.org/debian-lts-announce/2024/01/msg00005.htmlMailing List, Third Party Advisory
Other references
Other vulnerabilities in Linux Kernel
- 9.8 Critical severity
- 7.0 High severity
- 7.8 High severity
- 7.1 High severity
- 7.0 High severity
- 7.8 High severity
Recent Out-of-bounds Write vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
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