Security readout for executives and security teams
Plain-English summary
CVE-2021-39598 is a denial-of-service issue in swftools through 20200710. Malformed input can trigger a NULL pointer dereference in callcode() in code.c, causing the tool to crash. Business impact depends on whether swftools is used in production file-processing workflows.
Executive priority
Prioritize where swftools supports customer-facing uploads, document conversion, or automated ingestion. This is primarily an availability risk, not a confirmed data theft or code execution issue based on the supplied evidence.
Technical view
The CVE record identifies a NULL pointer dereference in swftools callcode() in code.c. The provided sources do not include CVSS, CWE, exploit prerequisites, a fixed version, or patch details. Treat this as an input-handling crash risk for swftools parsing or conversion paths.
Likely exposure
Exposure is likely limited to systems that run swftools through 20200710, especially automated services processing untrusted SWF or related files. The source bundle does not identify packaged distributions, downstream products, or internet-facing default services.
Exploitation context
The source states an attacker can cause denial of service. KEV is false, and the supplied sources do not show active exploitation, public weaponization, or exploitation in the wild.
Researcher notes
Evidence is sparse. The public record names the vulnerable function and DoS outcome, but not root-cause detail, patch commit, affected CPEs, CVSS, or reliable exploit conditions. Further validation should start with the GitHub issue and vendor repository history.
Mitigation direction
- Inventory all systems and containers using swftools.
- Avoid processing untrusted files with affected swftools builds.
- Run swftools in isolated, resource-constrained worker environments.
- Check upstream or distributor guidance for fixed builds or patches.
- Monitor conversion services for crashes and repeated malformed input failures.
Validation and detection
- Confirm installed swftools versions against the through-20200710 affected statement.
- Identify workflows where swftools processes user-supplied files.
- Review crash logs for NULL dereference or callcode-related failures.
- Verify processing workers recover safely after parser crashes.
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-2021-39598 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/145CVE 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.