Cyber Resilience

CVE-2023-6246

Memory Safety in Fedoraproject Fedora 38 … 39

Public PoCMemory Safety
Published
31 January 2024
Modified
12 May 2026
CVSS Score v3.1 8.4
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.048 91th percentile
Risk Priority 77 floored blend · peak EPSS

Summary

CVE-2023-6246 is a high-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Fedoraproject Fedora. Its CVSS base score is 8.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — 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.

A heap-based buffer overflow exists in the __vsyslog_internal function of the glibc library, which is invoked by the syslog and vsyslog functions. The flaw is triggered when openlog has not been called or was called with a NULL ident argument and the program name, derived from the basename of argv[0], exceeds 1024 bytes. It affects glibc versions 2.36 and later and carries a CVSS score of 8.4.

An unauthenticated local attacker can exploit the issue simply by executing a program whose name is longer than 1024 bytes and that invokes syslog or vsyslog without a prior openlog call. Successful exploitation may result in an application crash or local privilege escalation to root.

Public proof-of-concept code has been posted to Packet Storm and Full Disclosure, and the EPSS score has reached a peak of 0.2914 with a current value of 0.2696. No information on in-the-wild exploitation is provided in the available references.

EU & UK References

Vulnerability Data

A heap-based buffer overflow was found in the __vsyslog_internal function of the glibc library. This function is called by the syslog and vsyslog functions. This issue occurs when the openlog function was not called, or called with the ident argument…

more

set to NULL, and the program name (the basename of argv[0]) is bigger than 1024 bytes, resulting in an application crash or local privilege escalation. This issue affects glibc 2.36 and newer.

CWE(s)
CWE-122CWE-787

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-6779Same product: Fedoraproject Fedora
CVE-2026-5450Same product: Gnu Glibc
CVE-2023-25139Same product: Gnu Glibc
CVE-2024-3516Same product: Fedoraproject Fedora
CVE-2024-21795Same product: Fedoraproject Fedora
CVE-2024-1283Same product: Fedoraproject Fedora
CVE-2023-4322Same product: Fedoraproject Fedora
CVE-2024-4559Same product: Fedoraproject Fedora
CVE-2024-5835Same product: Fedoraproject Fedora
CVE-2023-4016Same product: Fedoraproject Fedora

Affected Assets

gnu
glibc
2.36 — 2.39
fedoraproject
fedora
38, 39

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.4.1

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation (including fuzzing and memory-error detectors) can discover heap overflows after they have been coded.

SI-10 Information Input Validation good match

Input validation enforces bounds checking on data written to heap buffers, directly stopping the overflow condition from being introduced.

SA-15 Development Process, Standards, and Tools partial match

Requiring documented secure-development standards and tools can mandate bounds-checked coding practices that avoid the weakness.

SA-8 Security and Privacy Engineering Principles partial match

Security engineering principles require use of memory-safe constructs and bounds-checked allocation routines that avoid introducing heap overflows.

SI-16 Memory Protection partial match

Memory-protection mechanisms limit the ability of a heap overflow to execute attacker-controlled code or corrupt adjacent structures.

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 full match
prevents

Secure-development practices directly require bounds checking and safe memory handling that prevent heap overflows.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover heap-overflow flaws but does not prevent their introduction in code.

PR.PS-02 partial match
prevents

Timely patching removes known heap-overflow instances after they exist.

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.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development and acceptance can detect heap overflows before release.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates practices that reduce the likelihood of introducing heap overflows.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify bounds-checking and safe memory APIs that mitigate heap overflows.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture and engineering principles include memory-safety and input-validation controls that address heap overflows.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly prescribe techniques (safe functions, bounds checks) that prevent heap-based buffer overflows.

A.8.32 Change management partial match
prevents

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

References