CVE-2023-31973

Exp

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.

Published: 2023-05-09 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-31973 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.14%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2023-31973

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2023-31973

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-10 0.05% 0.14% +0.09%
2 2025-03-30 0.12% 0.05% -0.07%
3 2025-03-29 — 0.12% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-31973

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2023-31973

OS Trackers for CVE-2023-31973

vendor priority summary link
alpine — CVE-2023-31973: 1 source package rows (yasm); 5 state rows across 5 repos (3.17-main, 3.18-main, 3.19-community, 3.20-community, edge-community); fixed 0, open 5. https://security.alpinelinux.org/vuln/CVE-2023-31973
debian unimportant CVE-2023-31973 unimportant priority: Debian including 1 source packages (yasm), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 5. https://security-tracker.debian.org/tracker/CVE-2023-31973
suse medium CVE-2023-31973 severity moderate: SUSE including 2 source package names (yasm, yasm-devel), 34 product×package rows across 18 product lines (SUSE CaaS Platform 4.0, SUSE Enterprise Storage 7, … (18 product lines)): Will Not Fix 34. https://www.suse.com/security/cve/CVE-2023-31973/
ubuntu medium CVE-2023-31973 medium priority: Ubuntu including 1 source packages (yasm), 10 status rows across 10 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, trusty, upstream, xenial): not-affected 5, ignored 4, needs-triage 1. https://ubuntu.com/security/CVE-2023-31973

Affected software / configurations for CVE-2023-31973

Vendor Product Version Raw CPE
tortall yasm 1.3.0 cpe:2.3:a:tortall:yasm:1.3.0:*:*:*:*:*:*:*

References for CVE-2023-31973

URL Tags
https://github.com/yasm/yasm/issues/207 Exploit Issue Tracking
cvelogic Threat Intelligence