Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2025-21772 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Linux Linux Kernel. Its CVSS base score is 7.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 13th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2025-21772 is a vulnerability in the Linux kernel's MAC partition table parsing code, stemming from improper handling of malformed or bogus partition tables. Specifically, it addresses issues such as failing to call put_dev_sector() after a successful read_part_sector() during bailout for invalid partoffset values, processing absurd sector sizes (e.g., 0xfff bytes) that cause partition entries to straddle sector boundaries and lead to out-of-bounds memory access, and assuming NUL-terminated strings in partition names by using strlen() and strcmp() instead of safer strnlen() and strncmp(). This results in a CWE-787 (Out-of-bounds Write) condition with a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).
A local attacker with low privileges (PR:L) can exploit this vulnerability with low complexity by presenting a crafted disk image or device with a malicious MAC partition table to a system during partition probing. Successful exploitation grants high-impact confidentiality, integrity, and availability consequences, potentially allowing arbitrary code execution, data corruption, or denial of service through out-of-bounds memory writes.
Mitigation requires applying the upstream kernel patches from the provided stable branch commits, including 213ba5bd81b7e97ac6e6190b8f3bc6ba76123625, 27a39d006f85e869be68c1d5d2ce05e5d6445bf5, 40a35d14f3c0dc72b689061ec72fc9b193f37d1f, 6578717ebca91678131d2b1f4ba4258e60536e9f, and 7fa9706722882f634090bfc9af642bf9ed719e27, which resolve the parsing flaws and prevent the identified memory safety issues.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-5153
Vulnerability Data
In the Linux kernel, the following vulnerability has been resolved: partitions: mac: fix handling of bogus partition table Fix several issues in partition probing: - The bailout for a bad partoffset must use put_dev_sector(), since the preceding read_part_sector() succeeded. -…
more
If the partition table claims a silly sector size like 0xfff bytes (which results in partition table entries straddling sector boundaries), bail out instead of accessing out-of-bounds memory. - We must not assume that the partition table contains proper NUL termination - use strnlen() and strncmp() instead of strlen() and strcmp().
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation (including fuzzing and bounds checks) finds out-of-bounds write flaws before deployment.
Requiring documented secure-development standards and tools can mandate bounds-checked coding practices that avoid the weakness.
Input validation can structurally reject or sanitize data that would otherwise trigger an out-of-bounds write.
Memory-protection mechanisms limit the exploitability and blast radius of a successful out-of-bounds write.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure-development practices (static analysis, bounds checking, code review) are the primary means of preventing out-of-bounds writes.
Vulnerability scanning and recording can discover out-of-bounds write flaws so they can be remediated.
Patching or replacing vulnerable software directly eliminates known instances of this coding weakness.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development and acceptance can detect and prevent out-of-bounds write defects.
Secure development life cycle mandates practices that prevent out-of-bounds writes.
Application security requirements can specify bounds-checking and safe memory handling.
Secure architecture and engineering principles reduce the likelihood of buffer overflows.
Secure coding directly addresses out-of-bounds writes through language choice and coding standards.
Change management can enforce review gates that catch unsafe memory operations before deployment.