Linux: Out-of-bounds Write
CVE-2024-56626 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 1aea5c9470be2c7129704fb1b9562b1e3e0576f8, 8cd7490fc0f268883e86e840cda5311257af69ca, 164d3597d26d9acff5d5b8bc3208bdcca942dd6a 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 0.71% chance of exploitation within 30 days, higher than 54% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 1aea5c9470be2c7129704fb1b9562b1e3e0576f8 or 8cd7490fc0f268883e86e840cda5311257af69ca or 164d3597d26d9acff5d5b8bc3208bdcca942dd6a or c5797f195c67132d061d29c57a7c6d30530686f0, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.15.176 or 6.1.120 or 6.6.66 or 6.12.5, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, 1aea5c9470be2c7129704fb1b9562b1e3e0576f8; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, 8cd7490fc0f268883e86e840cda5311257af69ca; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, 164d3597d26d9acff5d5b8bc3208bdcca942dd6a; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, c5797f195c67132d061d29c57a7c6d30530686f0; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, 313dab082289e460391c82d855430ec8a28ddf81; 5.15 | 1aea5c9470be2c7129704fb1b9562b1e3e0576f8, 8cd7490fc0f268883e86e840cda5311257af69ca, 164d3597d26d9acff5d5b8bc3208bdcca942dd6a, c5797f195c67132d061d29c57a7c6d30530686f0, 313dab082289e460391c82d855430ec8a28ddf81 |
| Linux | Linux Kernel | 5.15 up to, but not including, 5.15.176; 5.16 up to, but not including, 6.1.120; 6.2 up to, but not including, 6.6.66; 6.7 up to, but not including, 6.12.5; 6.13 | 5.15.176, 6.1.120, 6.6.66, 6.12.5 |
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 system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.8 | High | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix Out-of-Bounds Write in ksmbd_vfs_stream_write An offset from client could be a negative value, It could allows to write data outside the bounds of the allocated buffer. Note that this issue is coming when setting 'vfs objects = streams_xattr parameter' in ksmbd.conf.
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.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/164d3597d26d9acff5d5b8bc3208bdcca942dd6a
- git.kernel.org/stable/c/1aea5c9470be2c7129704fb1b9562b1e3e0576f8
- git.kernel.org/stable/c/313dab082289e460391c82d855430ec8a28ddf81
- git.kernel.org/stable/c/8cd7490fc0f268883e86e840cda5311257af69ca
- git.kernel.org/stable/c/c5797f195c67132d061d29c57a7c6d30530686f0
Other references
Recent Out-of-bounds Write vulnerabilities
- 7.5 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
Linux Kernel Out-of-Bounds Access Exploited
- 7.8 High severity
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