Security readout for executives and security teams
Plain-English summary
CVE-2021-46312 is a denial-of-service issue in djvulibre 3.5.28. A malformed or problematic DjVu processing path can trigger a divide-by-zero crash. The business impact is mainly availability: services or workflows that automatically process DjVu documents could be disrupted.
Executive priority
Treat as a targeted availability issue. It is not currently supported by evidence of active exploitation, but document-processing services should patch promptly because crafted files can disrupt operations.
Technical view
The reported flaw is in IW44EncodeCodec.cpp in djvulibre 3.5.28 and allows denial of service through divide by zero. The source bundle does not provide CVSS, CWE, proof of active exploitation, or exact fixed upstream version details.
Likely exposure
Exposure is most likely on Linux systems, servers, containers, or desktop workflows using djvulibre or libdjvulibre to process DjVu files. Risk increases where untrusted documents are accepted or processed automatically.
Exploitation context
The bundle marks KEV as false and provides no cited evidence of active exploitation. The known impact is denial of service, not data theft or code execution, based on the supplied description.
Researcher notes
Evidence is limited to a divide-by-zero denial-of-service report and distribution advisories. The affected component is identified, but this prompt does not include CVSS, CWE, exploit maturity, or exact remediation version data.
Mitigation direction
- Apply djvulibre or libdjvulibre updates from OS vendor advisories.
- Check Fedora and Debian guidance for fixed package versions.
- Restrict automated processing of untrusted DjVu files where feasible.
- Prioritize internet-facing or batch document-processing systems first.
Validation and detection
- Inventory systems and containers with djvulibre or libdjvulibre installed.
- Confirm installed package versions against Fedora or Debian advisories.
- Identify applications that automatically process DjVu files.
- Review crash logs for djvulibre-related divide-by-zero failures.
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-2021-46312 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://sourceforge.net/p/djvu/bugs/344/CVE reference
- FEDORA-2024-d20163632fCVE reference · vendor-advisory
- FEDORA-2024-891c09df97CVE reference · vendor-advisory
- FEDORA-2024-e8b9bedd36CVE reference · vendor-advisory
- https://lists.debian.org/debian-lts-announce/2025/07/msg00007.htmlCVE reference
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/HN4JOIBNMJMW2NQSGT6DCDCQZJ2ROFM7/CVE reference
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/XEEGAR4WUF6LTOJEHSON7I2MBTPFTVR5/CVE reference
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.