Is CVE-2021-42778 in the CISA KEV catalog?

No. CVE-2021-42778 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-42778?

CVE-2021-42778 has a CVSS v3 base score of 5.3 (MEDIUM).

What is the EPSS score for CVE-2021-42778?

CVE-2021-42778 has an EPSS score of 2.03% (79th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-42778?

Upgrade opensc on debian 11 to 0.21.0-1+deb11u1 or later.

CVE & CISA-KEV Catalog

CVE-2021-42778

MEDIUMEPSS 79th pctl

5.3

CVSS v3

NVD

Description

A heap double free issue was found in Opensc before version 0.22.0 in sc_pkcs15_free_tokeninfo.

CWE-672 CWE-415

How to fix

Remediation Available

openscDebian

Fixed in:0.21.0-1+deb11u1CVE-2021-42778

Fixed in:0.22.0-1CVE-2021-42778

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityLow

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Exploit Intelligence

2.03%probability of exploitation in 30 days

79thpercentile

Elevated risk: more likely to be exploited than 79% of all known CVEs.

References

Patch3

Third-Party Advisory1

security.gentoo.org

Other references1

lists.debian.org

Embed a live status badge for CVE-2021-42778

Markdown

[![CVE-2021-42778](https://tridentstack.com/cve/badge/CVE-2021-42778.svg)](https://tridentstack.com/cve/CVE-2021-42778)

HTML

<a href="https://tridentstack.com/cve/CVE-2021-42778"><img src="https://tridentstack.com/cve/badge/CVE-2021-42778.svg" alt="CVE-2021-42778"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-11-03.