CVE-2023-4535

Sensitive-data exposure via unchecked MyEID padding read

Published Nov 6, 2023 · Updated Nov 21, 2025

Out-of-bounds read in OpenSC's MyEID driver on Red Hat Enterprise Linux 9 allows physically proximate attackers to access sensitive data. The myeid_enc_dec_sym function walks padding bytes in a symmetric-decryption response without keeping the read within the returned plaintext buffer. Exploitation requires user interaction plus a crafted USB device or smart card that controls APDU responses; symmetric-key use is uncommon, so most deployments are not exposed.

CVSS severity4.5
Medium
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in OpenSC's MyEID driver on Red Hat Enterprise Linux 9 allows physically proximate attackers to access sensitive data. The myeid_enc_dec_sym function walks padding bytes in a symmetric-decryption response without keeping the read within the returned plaintext buffer. Exploitation requires user interaction plus a crafted USB device or smart card that controls APDU responses; symmetric-key use is uncommon, so most deployments are not exposed.

The record

CVE
CVE-2023-4535
Published
Nov 6, 2023
Updated
Nov 21, 2025
Vendor
Red Hat
Product
Red Hat Enterprise Linux 9
Classifications
CWE-125, T1200
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 6, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 21, 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 9Affected versions are unavailable in this record.

Published CVSS scores

3.8NIST NVDCVSS:3.1/AV:P/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L
4.5OpenSCCVSS:3.0/AV:P/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:L
4.5Red Hat, Inc.CVSS:3.1/AV:P/AC:H/PR:N/UI:R/S:C/C:L/I:L/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.

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

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
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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