CVE-2023-40661

Card-enrollment compromise via unchecked APDU buffer lengths

Published Nov 6, 2023 · Updated Nov 6, 2025

Memory-safety flaws in OpenSC before 0.24.0 allow physically proximate attackers to corrupt card-enrollment operations via crafted APDU replies. Multiple pkcs15-init and libopensc paths trust card-supplied lengths before copying, indexing, or subtracting buffer offsets, causing overflows, underflows, and an out-of-bounds write. Exploitation requires a crafted USB device or smart card during active enrollment; ordinary PKCS#11 use is not exposed, and key generation or certificate loading can be compromised.

CVSS severity5.4
Medium
EPSS probability1.17%
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 0.24.0 allow physically proximate attackers to corrupt card-enrollment operations via crafted APDU replies. Multiple pkcs15-init and libopensc paths trust card-supplied lengths before copying, indexing, or subtracting buffer offsets, causing overflows, underflows, and an out-of-bounds write. Exploitation requires a crafted USB device or smart card during active enrollment; ordinary PKCS#11 use is not exposed, and key generation or certificate loading can be compromised.

The record

CVE
CVE-2023-40661
Published
Nov 6, 2023
Updated
Nov 6, 2025
Vendor
Red Hat
Product
Red Hat Enterprise Linux 8
Classifications
CWE-119, T1200
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 6, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 6, 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 versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

Red Hat · Red Hat Enterprise Linux 8Affected versions are unavailable in this record.
OpenSC Project · OpenSCversion=0 <0.24.0
Red Hat · Red Hat Enterprise Linux 9Affected versions are unavailable in this record.

Published CVSS scores

6.4NIST NVDCVSS:3.1/AV:P/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
5.4Red HatCVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H
5.4Amazon LinuxCVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
T1200Hardware Additions

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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