Security readout for executives and security teams
Plain-English summary
CVE-2021-39585 is a denial-of-service issue in swftools through 20200710. A crafted input can trigger a NULL pointer dereference and crash processing. The public sources do not provide CVSS, a fixed version, or evidence of active exploitation.
Executive priority
Prioritize based on business reliance on SWF processing. This is not currently supported as actively exploited, but untrusted file-processing pipelines could suffer service disruption if vulnerable swftools is exposed.
Technical view
The flaw is reported in traits_dump() in abc.c, where a NULL pointer dereference can occur. The stated security impact is denial of service. The CVE record identifies swftools through 20200710, but the source bundle does not provide affected CPEs, patch details, or exploit-in-the-wild evidence.
Likely exposure
Exposure is most likely where swftools through 20200710 processes untrusted or externally supplied SWF or ABC-related content. The sources do not identify specific downstream packages, operating systems, cloud services, or default deployments.
Exploitation context
The CVE describes attacker-caused denial of service, but KEV is false and the supplied sources do not show active exploitation. Treat exploitability details as incomplete; avoid assuming remote reachability unless swftools is reachable through a file-processing workflow.
Researcher notes
The record is sparse: no CVSS, CWE, CPE, patch, or detailed affected platform list is supplied. The reliable technical claim is a NULL pointer dereference in traits_dump() in abc.c causing denial of service in swftools through 20200710.
Mitigation direction
- Inventory swftools usage and identify versions through 20200710.
- Check upstream or package-maintainer guidance for a fixed release or advisory.
- Avoid processing untrusted SWF-related files with affected builds.
- Isolate file-processing jobs to limit crash impact on critical services.
- Disable or replace swftools where it is not operationally required.
Validation and detection
- Confirm whether swftools is installed in production, CI, or content-processing workers.
- Map workflows that accept SWF-related files from users or third parties.
- Check application and worker logs for swftools crashes during parsing.
- Verify package-manager or upstream records for any fixed version before remediation.
- Document whether the vulnerable code path is reachable in your environment.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2021-39585 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/matthiaskramm/swftools/issues/133CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.