kernel: Improper Validation of Array Index
CVE-2023-2008 is a high-severity improper validation of array index vulnerability in kernel from 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 5.4.202, 5.10.127, 5.15.51 as the first without the flaw, so updating kernel to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.01% chance of exploitation within 30 days, higher than 64% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update kernel to 5.4.202 or 5.10.127 or 5.15.51 or 5.18.8, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.19 or 5.4.202 or 5.10.127 or 5.15.51, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | kernel | 4.20 up to, but not including, 5.4.202; 5.5 up to, but not including, 5.10.127; 5.11 up to, but not including, 5.15.51; 5.16 up to, but not including, 5.18.8 | 5.4.202, 5.10.127, 5.15.51, 5.18.8 |
| Red Hat | Red Hat Enterprise Linux 9 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 9.0 Extended Update Support | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 6 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 7 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8 | Not specified in the record | Not stated |
| Linux | Linux Kernel | before 5.19; 4.20 up to, but not including, 5.4.202; 5.5 up to, but not including, 5.10.127; 5.11 up to, but not including, 5.15.51; 5.16 up to, but not including, 5.18.8; 5.19 | 5.19, 5.4.202, 5.10.127, 5.15.51, 5.18.8 |
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 | 8.2 | High | CNA (redhat.com) |
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
Official description
A flaw was found in the Linux kernel's udmabuf device driver, within a fault handler. This issue occurs due to the lack of proper validation of user-supplied data, which can result in memory access past the end of an array. This may allow an attacker to escalate privileges and execute arbitrary code in the context of the kernel.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Validation of Array Index
The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.
How developers prevent this class of flaw
- Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, Ada allows the programmer to constrain the values of a variable and languages such as Java and Ruby will allow the programmer to handle exceptions when an out-of-bounds index is accessed.
- Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment. For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND.
More Improper Validation of Array Index vulnerabilities (CWE-129)
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
- bugzilla.redhat.com/show_bug.cgi?id=2186862Issue Tracking, Third Party Advisory
- github.com/torvalds/linux/commit/05b252cccb2e5c3f56119d25de684b4f810ba4
Third-party and government advisories
- zerodayinitiative.com/advisories/ZDI-23-441/Third Party Advisory, VDB Entry
- security.netapp.com/advisory/ntap-20230517-0007/Third Party Advisory
Other references
Other vulnerabilities in kernel
- 7.1 High severity
- 7.8 High severity
Linux Kernel Use-After-Free Exploited
- 7.8 High severity
- 7.1 High severity
- 7.4 High severity
- 7.0 High severity
Recent Improper Validation of Array Index vulnerabilities
- 8.8 High severity
- 7.5 High severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
- 7.8 High severity
Spotted an error? Tell us.