Cyber Resilience

CVE-2023-6240

Redhat Enterprise Linux 7.0 … 9.0

Published
04 February 2024
Modified
21 November 2024
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
EPSS Score 0.0097 59th percentile
Risk Priority 51 floored blend · peak EPSS

Summary

CVE-2023-6240 is a medium-severity Observable Discrepancy (CWE-203) vulnerability in Redhat Enterprise Linux. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Account Discovery (T1087); ranked in the top 41% of CVEs by exploit likelihood; 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

Vulnerability Data

A Marvin vulnerability side-channel leakage was found in the RSA decryption operation in the Linux Kernel. This issue may allow a network attacker to decrypt ciphertexts or forge signatures, limiting the services that use that private key.

CWE(s)
CWE-203

Related Threats

MITRE ATT&CK Enterprise Techniques

T1087 Account Discovery Discovery
Adversaries may attempt to get a listing of valid accounts, usernames, or email addresses on a system or within a compromised environment.
attack.mitre.org →
T1110 Brute Force Credential Access
Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained.
attack.mitre.org →
T1595 Active Scanning Reconnaissance
Adversaries may execute active reconnaissance scans to gather information that can be used during targeting.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-0564Same product: Linux Linux Kernel
CVE-2023-3640Same product: Linux Linux Kernel
CVE-2024-47678Same product: Linux Linux Kernel
CVE-2024-50102Same product: Linux Linux Kernel
CVE-2024-0646Same product: Linux Linux Kernel
CVE-2023-7192Same product: Linux Linux Kernel
CVE-2023-28328Same product: Linux Linux Kernel
CVE-2023-2513Same product: Linux Linux Kernel
CVE-2023-4387Same product: Linux Linux Kernel
CVE-2023-5090Same product: Linux Linux Kernel

Affected Assets

linux
linux kernel
all versions
redhat
enterprise linux
7.0, 8.0, 9.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 1 hardening rule · 1 OS baseline
Validate
Prove the fix (OWASP ASVS)

—

Mitigating Controls (NIST 800-53 r5) AI

IA-6 Authentication Feedback good match

Obscures authentication feedback so that success/failure differences are not observable to attackers.

SI-11 Error Handling good match

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.

PR.PS-06 mostly match
prevents

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.

A.8.17 Clock synchronization none match
none

Accurate, synchronized timestamps reduce observable timing discrepancies that an attacker could exploit to infer sensitive information or distinguish between success and failure paths.

References