CVE-2022-49047
Published: 26 February 2025
Summary
CVE-2022-49047 is a high-severity Use After Free (CWE-416) 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 33.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 RA-5 (Vulnerability Monitoring and Scanning) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2022-49047 is a Use After Free (UAF) vulnerability in the Linux kernel's ep93xx clock subsystem. The flaw occurs in the ep93xx_clk_register_gate() function within arch/arm/mach-ep93xx/clock.c, where memory for a clock gate structure (psc) is freed on error (via kfree(psc)) but then dereferenced afterward (return &psc->hw), as detected by the Clang static analyzer. It affects the Linux kernel on ep93xx ARM architecture platforms and is classified under CWE-416 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 can exploit this vulnerability due to its low attack complexity and lack of user interaction requirements. Successful exploitation could grant high impacts on confidentiality, integrity, and availability, potentially enabling arbitrary kernel code execution, data corruption, or system crashes through manipulation of the freed memory in the clock registration process.
Mitigation is provided through kernel patches in stable trees, including commits 0f12166872da46c6b57ba2f1314bbf310b3bf017 and 3b68b08885217abd9c57ff9b3bb3eb173eee02a9 available at git.kernel.org. Systems running affected ep93xx kernel versions should apply these updates to prevent UAF exploitation.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2022-55156
Vulnerability details
In the Linux kernel, the following vulnerability has been resolved: ep93xx: clock: Fix UAF in ep93xx_clk_register_gate() arch/arm/mach-ep93xx/clock.c:154:2: warning: Use of memory after it is freed [clang-analyzer-unix.Malloc] arch/arm/mach-ep93xx/clock.c:151:2: note: Taking true branch if (IS_ERR(clk)) ^ arch/arm/mach-ep93xx/clock.c:152:3: note: Memory is released kfree(psc);…
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^~~~~~~~~~ arch/arm/mach-ep93xx/clock.c:154:2: note: Use of memory after it is freed return &psc->hw; ^ ~~~~~~~~
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Local kernel UAF enabling arbitrary code execution and privilege escalation from low-privileged context on affected ARM platforms.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires timely remediation of the UAF flaw in ep93xx_clk_register_gate() through application of specific kernel patches.
Enables proactive identification of CVE-2022-49047 via vulnerability scanning of kernel versions on ep93xx platforms.
Provides memory protection mechanisms that mitigate exploitation of the UAF vulnerability even if unpatched.