Security readout for executives and security teams
Plain-English summary
CVE-2021-28856 is a crash risk in Deark before v1.5.8. A specially crafted input file can trigger a division-by-zero condition. The likely business impact is denial of service in workflows that automatically inspect, convert, or extract untrusted files.
Executive priority
Address in normal vulnerability remediation cycles, faster for automated untrusted-file processing. The evidence supports denial-of-service concern, not system compromise or active exploitation.
Technical view
The CVE description identifies a division by zero in Deark's src/fmtutil.c tied to the pixelsize value. The affected range is described as Deark before v1.5.8, with a linked upstream commit. Public metadata does not provide CVSS, CWE, or detailed affected package identifiers.
Likely exposure
Exposure is most likely where Deark processes files from users, customers, email, archives, malware triage, or automated content pipelines. Systems using Deark only for trusted local files have lower practical exposure.
Exploitation context
The source bundle includes a public PoC repository reference, but CVE metadata does not show KEV listing or confirmed active exploitation. Treat this as plausible denial-of-service risk, not evidence of real-world exploitation.
Researcher notes
Evidence is limited to the CVE description, an upstream commit, a researcher write-up, and a PoC repository reference. No CVSS vector, CWE mapping, or vendor advisory details were provided in the bundle.
Mitigation direction
- Upgrade Deark to v1.5.8 or later where available.
- Restrict Deark processing of untrusted files until updated.
- Run file-processing jobs with resource limits and isolation.
- Monitor the upstream Deark project for additional guidance.
- Prioritize internet-facing or automated ingestion workflows first.
Validation and detection
- Inventory systems, containers, and scripts that invoke Deark.
- Confirm installed Deark versions are v1.5.8 or later.
- Identify workflows that process untrusted or externally supplied files.
- Review crash logs for Deark failures during file parsing.
- Retest representative file-processing pipelines after upgrade.
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-2021-28856 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
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.