Security readout for executives and security teams
Plain-English summary
CVE-2021-42779 is a heap use-after-free flaw in OpenSC, reported as fixed before version 0.22.0. The practical business risk depends on where OpenSC is installed and used. The provided sources do not include CVSS, confirmed exploitation, or a detailed impact statement.
Executive priority
Treat this as a normal vulnerability-management item unless OpenSC is widely deployed in authentication workflows. Prioritize inventory and vendor-fixed package updates, but do not escalate as an emergency based on the supplied evidence.
Technical view
The issue is CWE-416 in OpenSC's sc_file_valid function. Public references include an OSS-Fuzz issue, Red Hat Bugzilla, an OpenSC commit, and Gentoo/Debian security advisories. The bundle states OpenSC before 0.22.0, but its affected-version field is inconsistent, so confirm package-specific status.
Likely exposure
Exposure is most likely on systems with the opensc package installed, especially where vendor packages predate the fixed OpenSC release or lack distribution backports. The source bundle does not identify specific operating systems beyond referenced Gentoo and Debian advisories.
Exploitation context
No active exploitation is supported by the provided sources. The CVE is not marked KEV, and the bundle provides no public exploit-status evidence. The OSS-Fuzz reference suggests discovery through fuzz testing, but details are not included here.
Researcher notes
Key uncertainty is impact detail: the bundle names a use-after-free in sc_file_valid but does not provide crashability, reachability, privileges, or exploitability analysis. The affected-version data should be reconciled against upstream and distro advisories.
Mitigation direction
- Inventory systems with opensc installed.
- Upgrade OpenSC to 0.22.0 or a vendor-fixed backport.
- Apply Gentoo, Debian, or other distribution security updates where applicable.
- Check vendor advisories if package versioning differs from upstream OpenSC.
Validation and detection
- Confirm installed opensc package versions across managed assets.
- Verify distribution changelogs reference CVE-2021-42779 or the upstream fix.
- Check whether OpenSC is present in container images and golden images.
- Track remediation exceptions where vendor-fixed versions retain older upstream numbers.
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-416: 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 lookupCVE-2021-42779 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://bugs.chromium.org/p/oss-fuzz/issues/detail?id=28843CVE reference
- https://bugzilla.redhat.com/show_bug.cgi?id=2016086CVE reference
- https://github.com/OpenSC/OpenSC/commit/1db88374CVE reference
- GLSA-202209-03CVE reference · vendor-advisory
- [debian-lts-announce] 20230621 [SECURITY] [DLA 3463-1] opensc security updateCVE reference · mailing-list
- https://lists.debian.org/debian-lts-announce/2024/12/msg00026.htmlCVE 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.
Use After Free
Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.