Security readout for executives and security teams
Plain-English summary
CVE-2021-31507 is a code execution flaw in OpenText Brava! Desktop 16.6.3.84. An attacker must trick a user into opening a malicious file or visiting a malicious page. Successful exploitation could run code with the user's application privileges, putting documents and endpoint integrity at risk.
Executive priority
Treat this as a high-priority endpoint remediation issue if Brava! Desktop 16.6.3.84 is present. Business urgency depends on whether users process external CGM or document files. No active exploitation evidence is provided, so prioritize based on installed footprint and exposure to untrusted content.
Technical view
The flaw is a CWE-121 stack-based buffer overflow in CGM file parsing. Brava! Desktop does not properly validate user-supplied data length before copying it to a stack buffer. ZDI identifies it as ZDI-CAN-12653. CVSS 3.0 is 7.8 with no privileges required and user interaction required.
Likely exposure
Exposure is limited to environments running OpenText Brava! Desktop 16.6.3.84, especially users who open CGM files or documents from untrusted sources. The source bundle does not identify other affected versions or products.
Exploitation context
The sources describe remote attacker code execution, but require user interaction. The CVSS vector is local with user interaction. The CVE is not marked KEV, and the provided sources do not state active exploitation.
Researcher notes
Validation should focus on version presence and document-handling workflows. The affected component is CGM parsing, with code execution in the current process. Do not assume broader OpenText product impact from the provided sources. No exploit status, patch version, or workaround is specified in the bundle.
Mitigation direction
- Inventory endpoints for OpenText Brava! Desktop 16.6.3.84.
- Check OpenText guidance for patched builds or vendor mitigations.
- Prioritize upgrade or removal where vulnerable versions are found.
- Restrict handling of unexpected CGM files where business permits.
- Use endpoint controls to inspect or quarantine suspicious document delivery.
Validation and detection
- Confirm installed Brava! Desktop versions on user workstations.
- Identify teams that open CGM or externally supplied document files.
- Review email and download telemetry for unexpected CGM delivery.
- Verify vendor patch or mitigation status before closing exposure.
- Document any compensating controls if patch timing is delayed.
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.
CWE-121: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution 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-2021-31507 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 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
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:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H1.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
7.8HighVector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.zerodayinitiative.com/advisories/ZDI-21-685/CVE 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.
Stack-based Buffer Overflow
Stack-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.