CVE-2021-34193

Application crashes via five memory-safety flaws

Published Aug 22, 2023 · Updated Nov 3, 2025

Memory-safety flaws in OpenSC before 0.22.0 allow attackers controlling smart-card responses to crash applications using the middleware. The duplicate identifier spans a double free in sc_pkcs15_free_tokeninfo, a use-after-free in sc_file_valid, a use-after-return in insert_pin, and heap and stack buffer overflows. A malicious or malfunctioning smart card must return crafted APDU data; the bounded reported consequence is process termination.

CVSS severity7.5
High
EPSS probability1.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory-safety flaws in OpenSC before 0.22.0 allow attackers controlling smart-card responses to crash applications using the middleware. The duplicate identifier spans a double free in sc_pkcs15_free_tokeninfo, a use-after-free in sc_file_valid, a use-after-return in insert_pin, and heap and stack buffer overflows. A malicious or malfunctioning smart card must return crafted APDU data; the bounded reported consequence is process termination.

The record

CVE
CVE-2021-34193
Published
Aug 22, 2023
Updated
Nov 3, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1499
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 22, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
4.3SUSECVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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