SB2026040263 - Multiple vulnerabilities in OpenSC

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Main Vulnerability Database SB2026040263

SB2026040263 - Multiple vulnerabilities in OpenSC

Published: April 2, 2026

Security Bulletin ID SB2026040263
Severity
Low
Patch available
YES
Number of vulnerabilities 5
Exploitation vector Physical access
Highest impact Data manipulation

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 5 secuirty vulnerabilities.


1) Out-of-bounds read (CVE-ID: CVE-2025-66037)

The vulnerability allows an attacker with physical access to disclose sensitive information, modify data, or cause a denial of service.

The vulnerability exists due to out-of-bounds read in sc_pkcs15_pubkey_from_spki_fields() in the X.509/SPKI handling path when parsing malformed X.509 certificate or SPKI data via the PIV/PKCS#15 reader path. An attacker with physical access can feed specially crafted certificate data to trigger an out-of-bounds heap read and disclose sensitive information, modify data, or cause a denial of service.

The issue occurs when a zero-length buffer is allocated and one byte is read past the end of that allocation. It is reachable through the shared certificate and public-key decoding logic, including the fuzz_pkcs15_reader and fuzz_pkcs15_crypt harnesses, and was observed as undefined behavior in a non-sanitized build under Valgrind.


2) Buffer Over-read (CVE-ID: CVE-2025-66038)

The vulnerability allows an attacker with physical access to disclose sensitive information, modify memory, or cause a denial of service.

The vulnerability exists due to out-of-bounds pointer return in sc_compacttlv_find_tag when parsing crafted compact-TLV data from untrusted cards or files. An attacker with physical access can provide a specially crafted compact-TLV buffer to disclose sensitive information, modify memory, or cause a denial of service.

The issue occurs because the function can return a pointer past the end of the buffer together with an unchecked length value, which may lead to downstream memory corruption when subsequent code dereferences the returned pointer.


3) Stack-based buffer overflow (CVE-ID: CVE-2025-66215)

The vulnerability allows an attacker with physical access to corrupt memory.

The vulnerability exists due to stack-based buffer overflow in the card-oberthur driver when processing specially crafted responses to APDUs from a crafted USB device or smart card. An attacker with physical access can present a crafted USB device or smart card to corrupt memory.

User interaction is required while a user or administrator uses a token, and the issue affects the oberthur card driver in libopensc.


4) Use of Uninitialized Variable (CVE-ID: CVE-2025-13763)

The vulnerability allows an attacker with physical access to disclose sensitive information, modify data, or cause a denial of service.

The vulnerability exists due to use of uninitialized variable in libopensc when processing crafted input through the fuzz_pkcs15init harness. An attacker with physical access can supply crafted input that triggers use of uninitialized memory to disclose sensitive information, modify data, or cause a denial of service.

The advisory reports 6 use-of-uninitialized-memory cases in functions including sc_asn1_read_tag(), get_cert_len(), asn1_encode_entry(), find_macro(), build_argv(), iasecc_process_fci, and iasecc_sdo_parse(). The reported security relevance is limited, and exploitation requires physical access with high attack complexity according to the provided CVSS vector.


5) Stack-based buffer overflow (CVE-ID: CVE-2025-49010)

The vulnerability allows an attacker with physical access to disclose sensitive information, modify data, or cause a denial of service.

The vulnerability exists due to a stack-based buffer overflow write in the GET RESPONSE handling in libopensc when processing specially crafted responses to APDU requests from a crafted USB device or smart card. An attacker with physical access can present a crafted USB device or smart card to trigger the overflow and disclose sensitive information, modify data, or cause a denial of service.

User interaction is required while a user or administrator is using a token, and the issue is considered high complexity.


Remediation

Install update from vendor's website.

References