Cyber Resilience

CVE-2022-23943

Memory Safety in Fedoraproject Fedora 34 … 36

High EPSSMemory Safety
Published
14 March 2022
Modified
01 May 2025
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.50 99th percentile
Risk Priority 95 floored blend · peak EPSS

Summary

CVE-2022-23943 is a critical-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Fedoraproject Fedora. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to CM-7 (Least Functionality) and SI-2 (Flaw Remediation) — 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-2022-23943 is an out-of-bounds write vulnerability in the mod_sed module of Apache HTTP Server that stems from integer overflow issues (CWE-190) and permits an attacker to overwrite heap memory with controlled data. It affects all 2.4.x releases through 2.4.52 and carries a CVSS 3.1 base score of 9.8.

An unauthenticated network attacker can trigger the flaw by sending a crafted request that reaches mod_sed, resulting in remote heap corruption that may be leveraged for arbitrary code execution, information disclosure, or denial of service.

Public advisories published by the Apache HTTP Server project, Debian LTS, and Fedora list updated packages that correct the defect; operators are advised to upgrade to a patched version of httpd 2.4.53 or later. The associated EPSS score reached a peak of 0.6855, indicating measurable post-disclosure exploitation interest.

EU & UK References

Vulnerability Data

Out-of-bounds Write vulnerability in mod_sed of Apache HTTP Server allows an attacker to overwrite heap memory with possibly attacker provided data. This issue affects Apache HTTP Server 2.4 version 2.4.52 and prior versions.

CWE(s)

Related Threats

Likely ATT&CK TechniquesAI

Techniques this vulnerability likely enables, inferred from its description, weakness type, and attributed-actor tradecraft. Confidence is per-technique.

T1190 Exploit Public-Facing Application Initial Accessconfidence: HIGH
Out-of-bounds write in Apache HTTP Server mod_sed allows unauthenticated remote attackers to corrupt heap memory via crafted requests, directly enabling exploitation of a public-facing web server.
T1068 Exploitation for Privilege Escalation Privilege Escalationconfidence: HIGH
Successful exploitation of the heap corruption can lead to arbitrary code execution, providing a direct path for privilege escalation on the server.
T1499.004 Application or System Exploitation Impactconfidence: MEDIUM
Heap corruption from the vulnerability can be abused to crash the httpd process, achieving denial of service.
inferred from description + CWE · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2021-26691Same product: Apache Http Server
CVE-2023-40186Same product: Debian Debian Linux
CVE-2021-44790Same product: Apache Http Server
CVE-2023-1810Same product: Debian Debian Linux
CVE-2023-40569Same product: Debian Debian Linux
CVE-2023-40567Same product: Debian Debian Linux
CVE-2024-26988Same product: Debian Debian Linux
CVE-2023-5849Same product: Debian Debian Linux
CVE-2023-4353Same product: Debian Debian Linux
CVE-2023-33204Same product: Debian Debian Linux

Affected Assets

apache
http server
2.4.0 — 2.4.53
fedoraproject
fedora
34, 35, 36
debian
debian linux
9.0
oracle
http server
12.2.1.3.0, 12.2.1.4.0
oracle
zfs storage appliance kit
8.8

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-2 Flaw Remediation
  • CM-7 Least Functionality
Detect
Catch it (NIST detect / respond)
  • RA-5 Vulnerability Monitoring and Scanning
Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V5.2.6

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires timely installation of security-relevant patches, which is the vendor-prescribed fix that eliminates the out-of-bounds write in mod_sed.

prevent

Requires disabling or restricting non-essential modules such as mod_sed, thereby removing the vulnerable code path before any crafted request can reach it.

detect

Mandates scanning for known vulnerable versions of httpd, enabling discovery of 2.4.52 and earlier instances that contain the integer-overflow flaw.

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 require use of safe arithmetic, bounds checks, and testing that prevent integer overflows.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover out-of-bounds write flaws so they can be remediated.

PR.PS-02 partial match
prevents

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.

detects

Security testing in development can detect integer overflows before release.

prevents

Secure SDLC mandates input validation and arithmetic checks that prevent integer overflows.

degrades

Application security requirements include bounds checking and safe arithmetic to avoid overflow conditions.

degrades

Secure architecture principles require defensive coding patterns that mitigate integer wraparound risks.

prevents

Secure coding standards explicitly forbid unsafe integer operations and mandate overflow-safe constructs.

prevents

Change management can enforce review gates that catch unsafe memory operations before deployment.

References