Linux: Out-of-bounds Write
CVE-2024-38667 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 ea22d4195cca13d5fdbc4d6555a2dfb8a7867a9e, 3090c06d50eaa91317f84bf3eac4c265e6cb8d44, 0c1f28c32a194303da630fca89481334b9547b80 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 0.23% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to ea22d4195cca13d5fdbc4d6555a2dfb8a7867a9e or 3090c06d50eaa91317f84bf3eac4c265e6cb8d44 or 0c1f28c32a194303da630fca89481334b9547b80 or a638b0461b58aa3205cd9d5f14d6f703d795b4af, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.93 or 6.6.33 or 6.9.4, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 2875fe0561569f82d0e63658ccf0d11ce7da8922 up to, but not including, ea22d4195cca13d5fdbc4d6555a2dfb8a7867a9e; 2875fe0561569f82d0e63658ccf0d11ce7da8922 up to, but not including, 3090c06d50eaa91317f84bf3eac4c265e6cb8d44; 2875fe0561569f82d0e63658ccf0d11ce7da8922 up to, but not including, 0c1f28c32a194303da630fca89481334b9547b80; 2875fe0561569f82d0e63658ccf0d11ce7da8922 up to, but not including, a638b0461b58aa3205cd9d5f14d6f703d795b4af; 5.7 | ea22d4195cca13d5fdbc4d6555a2dfb8a7867a9e, 3090c06d50eaa91317f84bf3eac4c265e6cb8d44, 0c1f28c32a194303da630fca89481334b9547b80, a638b0461b58aa3205cd9d5f14d6f703d795b4af |
| Linux | Linux Kernel | 5.7 up to, but not including, 6.1.93; 6.2 up to, but not including, 6.6.33; 6.7 up to, but not including, 6.9.4; 6.10 | 6.1.93, 6.6.33, 6.9.4 |
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.
Official description
In the Linux kernel, the following vulnerability has been resolved: riscv: prevent pt_regs corruption for secondary idle threads Top of the kernel thread stack should be reserved for pt_regs. However this is not the case for the idle threads of the secondary boot harts. Their stacks overlap with their pt_regs, so both may get corrupted. Similar issue has been fixed for the primary hart, see c7cdd96eca28 ("riscv: prevent stack corruption by reserving task_pt_regs(p) early"). However that fix was not propagated to the secondary harts. The problem has been noticed in some CPU hotplug tests with V enabled. The function smp_callin stored several registers on stack, corrupting top of pt_regs structure including status field. As a result, kernel attempted to save or restore inexistent V context.
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: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Out-of-bounds Write vulnerabilities
- 7.1 High severity
- 8.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.5 High severity
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