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Fencer Vulns
high 7.5

CVE-2021-34193 json

Stack overflow vulnerability in OpenSC smart card middleware before 0.23 via crafted responses to APDUs.

published 2023-08-22 3 y ago modified 2026-06-17 4 mo ago also EUVD-2021-20855

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.4%
EPSS 1.4% chance of exploitation in 30 days, percentile 72%
public exploits
0
none known

Summary

Stack overflow vulnerability in OpenSC smart card middleware before 0.23 via crafted responses to APDUs.

Patch / fix

  • opensc_project opensc 0.22.0
  • opensc Debian 14, Debian 13, Debian 12 0.22.0-1

debian advisories DEBIAN-CVE-2021-34193

  • opensc CBL-Mariner 2.0 0.23.0-1

azure linux advisories AZL-28094

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-34193 updated cvss 0.0

opensc: Stack overflow vulnerability in OpenSC smart card middleware

  • Red Hat Enterprise Linux 7 opensc Red Hat Enterprise Linux 8 opensc Red Hat Enterprise Linux 9 opensc
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.39% chance of exploitation in the next 30 days, higher than 72% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.