Linux: Off-by-one Error
CVE-2024-47686 is a high-severity off-by-one error vulnerability in Linux, with a CVSS 3.1 base score of 7.1 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 7a5bd2fb92388c51d267f6ce57c40f1cca8af1e0, 66e78ade976dbd9bea09166aa8d66afc0963cde4, 27f493e141823db052586010c1532b70b164507c 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 0.24% 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 7a5bd2fb92388c51d267f6ce57c40f1cca8af1e0 or 66e78ade976dbd9bea09166aa8d66afc0963cde4 or 27f493e141823db052586010c1532b70b164507c or ae59eaf36a1ad396e9f657ec9b8b52da6206ed5f, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.113 or 6.6.54 or 6.10.13 or 6.11.2, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 9645ccc7bd7a16cd73c3be9dee70cd702b03be37 up to, but not including, 7a5bd2fb92388c51d267f6ce57c40f1cca8af1e0; 9645ccc7bd7a16cd73c3be9dee70cd702b03be37 up to, but not including, 66e78ade976dbd9bea09166aa8d66afc0963cde4; 9645ccc7bd7a16cd73c3be9dee70cd702b03be37 up to, but not including, 27f493e141823db052586010c1532b70b164507c; 9645ccc7bd7a16cd73c3be9dee70cd702b03be37 up to, but not including, ae59eaf36a1ad396e9f657ec9b8b52da6206ed5f; 9645ccc7bd7a16cd73c3be9dee70cd702b03be37 up to, but not including, c7f06284a6427475e3df742215535ec3f6cd9662; 5.16 | 7a5bd2fb92388c51d267f6ce57c40f1cca8af1e0, 66e78ade976dbd9bea09166aa8d66afc0963cde4, 27f493e141823db052586010c1532b70b164507c, ae59eaf36a1ad396e9f657ec9b8b52da6206ed5f, c7f06284a6427475e3df742215535ec3f6cd9662 |
| Linux | Linux Kernel | 5.16 up to, but not including, 6.1.113; 6.2 up to, but not including, 6.6.54; 6.7 up to, but not including, 6.10.13; 6.11 up to, but not including, 6.11.2 | 6.1.113, 6.6.54, 6.10.13, 6.11.2 |
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
- NoneNothing can be modified.
- 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:N/A:H. Scored by NVD.
Official description
In the Linux kernel, the following vulnerability has been resolved: ep93xx: clock: Fix off by one in ep93xx_div_recalc_rate() The psc->div[] array has psc->num_div elements. These values come from when we call clk_hw_register_div(). It's adc_divisors and ARRAY_SIZE(adc_divisors)) and so on. So this condition needs to be >= instead of > to prevent an out of bounds read.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Off-by-one Error
A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value.
How developers prevent this class of flaw
- When copying character arrays or using character manipulation methods, the correct size parameter must be used to account for the null terminator that needs to be added at the end of the array. Some examples of functions susceptible to this weakness in C include strcpy(), strncpy(), strcat(), strncat(), printf(), sprintf(), scanf() and sscanf().
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
- git.kernel.org/stable/c/27f493e141823db052586010c1532b70b164507c
- git.kernel.org/stable/c/66e78ade976dbd9bea09166aa8d66afc0963cde4
- git.kernel.org/stable/c/7a5bd2fb92388c51d267f6ce57c40f1cca8af1e0
- git.kernel.org/stable/c/ae59eaf36a1ad396e9f657ec9b8b52da6206ed5f
- git.kernel.org/stable/c/c7f06284a6427475e3df742215535ec3f6cd9662
Other references
Recent Off-by-one Error vulnerabilities
- 7.8 High severity
- 7.1 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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