Security readout for executives and security teams
Plain-English summary
XNView 2.49.3 can crash or run attacker-controlled code when a user opens a malicious TIFF file. The business risk is workstation compromise through document handling, not a directly internet-exposed service. Sources do not show active exploitation.
Executive priority
Prioritize remediation for teams handling external image files, such as support, marketing, intake, and investigations. The issue is high impact but requires file opening, so urgency depends on XNView deployment and exposure to untrusted TIFFs.
Technical view
CVE-2021-28427 is a buffer overflow in XNView 2.49.3 triggered by a crafted TIFF file. CVSS 3.1 is 7.8 with local attack vector, low complexity, no privileges, required user interaction, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely on endpoints where XNView 2.49.3 is installed and used to open TIFF images from email, downloads, shared folders, or external media.
Exploitation context
The source bundle supports crafted-file exploitation with user interaction. It is not listed in CISA KEV, and no supplied source states active exploitation. Treat exploit status as unconfirmed.
Researcher notes
The CVE record gives sparse product metadata: affected vendor/product are listed as n/a, and no CWE is supplied. Rely on the description naming XNView 2.49.3 and the referenced XnView forum thread; validate fix status directly with vendor material.
Mitigation direction
- Inventory and remove or replace XNView 2.49.3 where not required.
- Check XnView vendor guidance for a fixed version or official workaround.
- Restrict opening TIFF files from untrusted or internet-sourced locations.
- Use endpoint controls to quarantine suspicious TIFF attachments and downloads.
- Prefer patched, managed image viewers for business workflows.
Validation and detection
- Identify endpoints with XNView 2.49.3 installed.
- Confirm whether XNView is associated with TIFF files by default.
- Review mail, web, and EDR telemetry for suspicious TIFF handling.
- Check whether vendor guidance names a fixed version or workaround.
- Document affected users who routinely process external image files.
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.
Execution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-28427 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
- High
- CVSS
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AC:L/AV:L/A:H/C:H/I:H/PR:N/S:U/UI:R
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 vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AC:L/AV:L/A:H/C:H/I:H/PR:N/S:U/UI:R1.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AC:L/AV:L/A:H/C:H/I:H/PR:N/S:U/UI:R
Source materials
- CVE List V5 sourceCVE List V5
- https://newsgroup.xnview.com/viewtopic.php?f=35&t=41035CVE 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.