CVE-2023-3640
Redhat Enterprise Linux 8.0 … 9.0
Raw vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2023-3640 is a high-severity Covert Timing Channel (CWE-385) vulnerability in Redhat Enterprise Linux. Its CVSS base score is 7.0 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Data Obfuscation (T1001); ranked in the top 48% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-44284
Vulnerability Data
A possible unauthorized memory access flaw was found in the Linux kernel's cpu_entry_area mapping of X86 CPU data to memory, where a user may guess the location of exception stacks or other important data. Based on the previous CVE-2023-0597, the…
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'Randomize per-cpu entry area' feature was implemented in /arch/x86/mm/cpu_entry_area.c, which works through the init_cea_offsets() function when KASLR is enabled. However, despite this feature, there is still a risk of per-cpu entry area leaks. This issue could allow a local user to gain access to some important data with memory in an expected location and potentially escalate their privileges on the system.
- 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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Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Directly targets covert timing channels by requiring identification and bandwidth estimation, enabling mitigation that reduces or eliminates their usability.
Misdirection can normalize or falsify responses to eliminate observable discrepancies that aid reconnaissance.
Prevents attackers from using observable differences in error responses to infer internal system details or state.
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 (reviews, testing) directly reduce introduction of timing-channel vulnerabilities in code.
Runtime monitoring of hardware/software behavior can detect anomalous timing patterns that indicate covert channels.
Vulnerability identification processes can surface timing-channel weaknesses during design or code analysis.
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.
Detailed logging can reveal timing anomalies but does not prevent covert timing channels.
Continuous monitoring may detect timing-based exfiltration but does not eliminate the channel itself.
Network segmentation reduces attack surface but does not address intra-process timing channels.
Network segregation limits external timing observation but not internal covert timing.
Secure architecture principles can include timing-channel countermeasures but are not specific.
Secure coding guidelines may recommend constant-time algorithms but coverage is not guaranteed.