Security readout for executives and security teams
Plain-English summary
CVE-2021-42613 is a memory-handling flaw in Halibut 1.2. A specially crafted text document can trigger a double free, causing denial of service and possibly other unspecified impact. Business urgency depends on whether Halibut processes untrusted documents in your environment.
Executive priority
Prioritize based on exposure to untrusted documents. This is not evidenced as actively exploited, but a crash in document-processing tooling can disrupt publishing, support, or build workflows if the vulnerable tool is reachable.
Technical view
The issue is described as a double free in cleanup_index in index.c in Halibut 1.2. The vulnerable path can be reached through a crafted text document. Public sources do not provide CVSS, CWE, a complete affected-product matrix, or confirmed impacts beyond denial of service and unspecified possible effects.
Likely exposure
Exposure is most likely where Halibut 1.2, or a distribution package containing it, processes documents from users, build pipelines, support queues, or other untrusted sources. Evidence in the bundle names Halibut 1.2 but does not enumerate all downstream packages or platforms.
Exploitation context
The CVE is not listed in KEV, and the provided sources do not state active exploitation. A public case-study reference includes a PoC section, so researchers should treat the input-triggered crash as reproducible without assuming broad weaponization.
Researcher notes
The source record lacks CVSS, CWE, and detailed remediation notes. The strongest technical facts are the double free location, Halibut 1.2 mention, crafted text document trigger, and Fedora advisory reference. Avoid expanding impact beyond denial of service or unspecified effects without new evidence.
Mitigation direction
- Identify whether Halibut is installed or embedded in document-generation workflows.
- Check Fedora and upstream Halibut guidance for fixed packages or replacement versions.
- Avoid processing untrusted Halibut input until patched or isolated.
- Run document processing in a constrained environment where crashes have limited impact.
Validation and detection
- Inventory systems and build images for Halibut 1.2 or distro packages.
- Review workflows that accept external text documents for Halibut processing.
- Confirm installed package versions against vendor advisory guidance.
- Monitor document-processing crashes linked to Halibut input handling.
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-2021-42613 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://carteryagemann.com/halibut-case-study.html#poc-halibut-winhelp-dfCVE reference · x_refsource_MISC
- FEDORA-2022-9a9abd295bCVE reference · vendor-advisory, x_refsource_FEDORA
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.