yasm 1.3.0 /nasm/nasm-pp.c expand_mmac_params use after free

HistoryDiffrelatejsonxmlCTI

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.3	$0-$5k	0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in yasm 1.3.0. Affected is the function expand_mmac_params of the file /nasm/nasm-pp.c. The manipulation leads to use after free. This vulnerability is referenced as CVE-2023-31973. No exploit is available.

Detailsinfo

A vulnerability was found in yasm 1.3.0 and classified as critical. This issue affects the function expand_mmac_params of the file /nasm/nasm-pp.c. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

The weakness was published 05/09/2023 as 207. The advisory is shared at github.com. The identification of this vulnerability is CVE-2023-31973 since 04/29/2023. Technical details are known, but no exploit is available.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2023-36262). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

yasm

Version

1.3.0

License

open-source

Website

Product: https://github.com/yasm/yasm/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 6.3

VulDB Base Score: 5.5
VulDB Temp Score: 5.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔍

CNA Base Score: 7.8
CNA Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍

Timelineinfo

04/29/2023 🔍
05/09/2023 +10 days 🔍
05/09/2023 +0 days 🔍
12/30/2025 +966 days 🔍

Sourcesinfo

Product: github.com

Advisory: 207
Status: Confirmed

CVE: CVE-2023-31973 (🔍)
GCVE (CVE): GCVE-0-2023-31973
GCVE (VulDB): GCVE-100-228425
EUVD: 🔍

Entryinfo

Created: 05/09/2023 16:26
Updated: 12/30/2025 01:23
Changes: 05/09/2023 16:26 (38), 06/01/2023 09:04 (11), 06/05/2024 16:04 (18), 08/02/2024 17:54 (11), 12/30/2025 01:23 (2)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.