Security readout for executives and security teams
Plain-English summary
CVE-2021-27347 is a memory-safety flaw in lrzip 0.631. A malicious compressed file can trigger a denial of service when processed. The main business risk is service interruption where lrzip handles untrusted archives automatically.
Executive priority
Treat this as a targeted availability risk, not a confirmed widespread compromise risk. Prioritize remediation where lrzip processes external files automatically or supports customer-facing workflows.
Technical view
The issue is a use-after-free in lzma_decompress_buf in stream.c in lrzip 0.631. The published description says a crafted compressed file can cause denial of service. No CVSS score, CWE, detailed affected range, or exploit-in-the-wild evidence is provided in the source bundle.
Likely exposure
Exposure is most likely where lrzip 0.631 is installed and used to decompress files from users, partners, email, backups, uploads, or automated pipelines. Systems that never process untrusted compressed files have lower practical exposure.
Exploitation context
The source bundle supports denial of service via crafted compressed file only. CISA KEV status is false, and no cited source states active exploitation. Evidence is insufficient to claim remote code execution or broader compromise.
Researcher notes
The public record is sparse: no CVSS, CWE, or complete affected range is included. Analysis should stay limited to lrzip 0.631, lzma_decompress_buf in stream.c, and denial of service unless vendor sources add more detail.
Mitigation direction
- Check whether lrzip is installed and whether version 0.631 is present.
- Review Debian DLA 2981-1 and vendor package guidance for fixed packages.
- Prioritize systems that process untrusted or automated archive inputs.
- Restrict lrzip processing of untrusted compressed files until updated.
- Monitor vendor advisories for affected version range and remediation details.
Validation and detection
- Inventory hosts, containers, and build images for lrzip installations.
- Confirm installed lrzip versions against vendor package metadata.
- Identify workflows that pass external compressed files to lrzip.
- Review crash reports or service failures tied to lrzip decompression.
- Verify patched packages are deployed after remediation.
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-2021-27347 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://github.com/ckolivas/lrzip/issues/165CVE reference · x_refsource_MISC
- [debian-lts-announce] 20220413 [SECURITY] [DLA 2981-1] lrzip security updateCVE reference · mailing-list, x_refsource_MLIST
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.