Cyber Resilience

CVE-2023-31973

Tortall Yasm 1.3.0

Public PoC
Published
09 May 2023
Modified
21 November 2024
CVSS Score v3.1 5.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
EPSS Score 0.0031 24th percentile
Risk Priority 42 floored blend · peak EPSS

Summary

CVE-2023-31973 is a medium-severity Missing Release of Memory after Effective Lifetime (CWE-401) vulnerability in Tortall Yasm. Its CVSS base score is 5.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 24th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability Data

yasm v1.3.0 was discovered to contain a use after free via the function expand_mmac_params at /nasm/nasm-pp.c. Note: Multiple third parties dispute this as a bug and not a vulnerability according to the YASM security policy.

CWE(s)
CWE-401CWE-590

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
attack.mitre.org →
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
attack.mitre.org →
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 →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-51258Same product: Tortall Yasm
CVE-2023-31972Same product: Tortall Yasm
CVE-2023-31974Same product: Tortall Yasm
CVE-2024-40979Shared CWE-401
CVE-2024-56775Shared CWE-401
CVE-2026-20810Shared CWE-590
CVE-2025-5899Shared CWE-590
CVE-2025-42996Shared CWE-590
CVE-2025-54899Shared CWE-590
CVE-2025-7006Shared CWE-590

Affected Assets

tortall
yasm
1.3.0

Mitigating Controls

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 enforce proper memory allocation/deallocation via coding standards, reviews, and tooling.

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 can detect unreleased memory, providing partial coverage of the weakness.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates memory-management practices that reduce missing-release defects.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify explicit memory-release rules, partially mitigating the weakness.

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

Secure system architecture and engineering principles include resource-management guidelines that address memory leaks.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly require proper allocation/deallocation, covering most of this weakness.

A.8.6 Capacity management partial match
finds

Capacity management may detect memory exhaustion symptoms but does not prevent the coding flaw.

References