CVE-2024-50102
Linux Kernel 6.4 – 6.11.6
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:NSummary
CVE-2024-50102 is a medium-severity Observable Discrepancy (CWE-203) vulnerability in Linux Linux Kernel. Its CVSS base score is 5.5 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Account Discovery (T1087); ranked at the 15th 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 IA-6 (Authentication Feedback) and SI-11 (Error Handling) — see the control section below for these in your framework.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2024-44577
Vulnerability Data
In the Linux kernel, the following vulnerability has been resolved: x86: fix user address masking non-canonical speculation issue It turns out that AMD has a "Meltdown Lite(tm)" issue with non-canonical accesses in kernel space. And so using just the high…
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bit to decide whether an access is in user space or kernel space ends up with the good old "leak speculative data" if you have the right gadget using the result: CVE-2020-12965 “Transient Execution of Non-Canonical Accesses“ Now, the kernel surrounds the access with a STAC/CLAC pair, and those instructions end up serializing execution on older Zen architectures, which closes the speculation window. But that was true only up until Zen 5, which renames the AC bit [1]. That improves performance of STAC/CLAC a lot, but also means that the speculation window is now open. Note that this affects not just the new address masking, but also the regular valid_user_address() check used by access_ok(), and the asm version of the sign bit check in the get_user() helpers. It does not affect put_user() or clear_user() variants, since there's no speculative result to be used in a gadget for those operations.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 1 hardening rule · 1 OS baseline
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Mitigating Controls (NIST 800-53 r5) AI
Obscures authentication feedback so that success/failure differences are not observable to attackers.
Requires error messages to avoid revealing exploitable details, directly stopping observable response discrepancies.
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 SDLC practices directly prevent observable response discrepancies via consistent error handling and timing.
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.
Accurate, synchronized timestamps reduce observable timing discrepancies that an attacker could exploit to infer sensitive information or distinguish between success and failure paths.