Linux: Out-of-bounds Write
CVE-2023-53543 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 baed19c108ac8287425b93a44985bbe9a0b1af8d, ff71709445ac033e6e250d971683110e4781c068, ea65e8b5e6b1a34deda7564f09c90e9e80db436a 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 0.17% 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 baed19c108ac8287425b93a44985bbe9a0b1af8d or ff71709445ac033e6e250d971683110e4781c068 or ea65e8b5e6b1a34deda7564f09c90e9e80db436a or 5d6ba607d6cb5c58a4ddf33381e18c83dbb4098f, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.15.209 or 6.1.47 or 6.4.12, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 447092100c7e71aa20469a270fcee441d807ed58 up to, but not including, baed19c108ac8287425b93a44985bbe9a0b1af8d; ad69dd0bf26b88ec6ab26f8bbe5cd74fbed7672a up to, but not including, ff71709445ac033e6e250d971683110e4781c068; ad69dd0bf26b88ec6ab26f8bbe5cd74fbed7672a up to, but not including, ea65e8b5e6b1a34deda7564f09c90e9e80db436a; ad69dd0bf26b88ec6ab26f8bbe5cd74fbed7672a up to, but not including, 5d6ba607d6cb5c58a4ddf33381e18c83dbb4098f; 5.15.198 up to, but not including, 5.15.209; 5.16 | baed19c108ac8287425b93a44985bbe9a0b1af8d, ff71709445ac033e6e250d971683110e4781c068, ea65e8b5e6b1a34deda7564f09c90e9e80db436a, 5d6ba607d6cb5c58a4ddf33381e18c83dbb4098f, 5.15.209 |
| Linux | Linux Kernel | 5.15.198 up to, but not including, 5.15.209; 5.16 up to, but not including, 6.1.47; 6.2 up to, but not including, 6.4.12; 6.5 | 5.15.209, 6.1.47, 6.4.12 |
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: vdpa: Add max vqp attr to vdpa_nl_policy for nlattr length check The vdpa_nl_policy structure is used to validate the nlattr when parsing the incoming nlmsg. It will ensure the attribute being described produces a valid nlattr pointer in info->attrs before entering into each handler in vdpa_nl_ops. That is to say, the missing part in vdpa_nl_policy may lead to illegal nlattr after parsing, which could lead to OOB read just like CVE-2023-3773. This patch adds the missing nla_policy for vdpa max vqp attr to avoid such bugs.
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
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 8.8 High severity
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