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CVE Record

CVE-2021-33468: An issue was discovered in yasm version 1.3.0.

An issue was discovered in yasm version 1.3.0. There is a use-after-free in error() in modules/preprocs/nasm/nasm-pp.c.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2021-33468 is a reported use-after-free flaw in Yasm 1.3.0. Yasm is used in build and assembly workflows, so business risk is mainly where systems process assembly or preprocessor input, especially from untrusted sources. The public bundle does not provide a CVSS score, confirmed impact, patch status, or active exploitation evidence.

Executive priority

Treat this as a targeted build-tool risk, not an internet-wide emergency based on current evidence. Prioritize inventory and containment where Yasm handles untrusted source input. Escalate if maintainers confirm code execution, a fixed release, or exploitation in the wild.

Technical view

The CVE describes a use-after-free in error() within modules/preprocs/nasm/nasm-pp.c in Yasm 1.3.0. Available sources identify the vulnerable component but do not establish exploitability beyond the memory-safety issue. No CWE, CVSS vector, affected CPEs, fixed version, or vendor mitigation is included in the supplied data.

Likely exposure

Exposure is likely limited to environments with Yasm 1.3.0 installed or embedded in build tooling. Risk increases where CI, packaging, or developer systems process untrusted assembly, NASM preprocessor input, or third-party source trees. Systems without Yasm, or with only trusted local inputs, have lower apparent exposure.

Exploitation context

The source bundle does not show CISA KEV listing, active exploitation, or weaponized public use. References include a GitHub issue and gist, but the supplied evidence does not confirm real-world attacks, remote reachability, privilege impact, or reliable code execution.

Researcher notes

The record is sparse: it names Yasm 1.3.0 and a use-after-free in nasm-pp.c error handling, but lacks CVSS, CWE, fixed version, and reachability details. Focus validation on whether the vulnerable NASM preprocessor path is reachable in local build workflows and whether downstream packages patched it.

Mitigation direction

  • Inventory Yasm installations and confirm whether version 1.3.0 is present.
  • Avoid processing untrusted assembly or preprocessor input with affected Yasm builds.
  • Check Yasm, OS distribution, and package maintainer guidance for fixed or backported builds.
  • Isolate build jobs that must process third-party source trees.
  • Prefer trusted inputs until vendor or maintainer remediation is confirmed.

Validation and detection

  • Check build images, developer workstations, and package manifests for Yasm 1.3.0.
  • Review CI jobs for assembly preprocessing or third-party source ingestion.
  • Confirm whether current packages include a maintainer fix or backport.
  • Use vendor-safe tests only; do not run proof-of-concept inputs in production.
  • Document any exposed build pipeline handling untrusted inputs.
Prepared
Confidence
medium
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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CVE-2021-33468 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
3Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.