Skip to main content

Opensc CVE-2023-40660

MEDIUM
Improper Authentication (CWE-287)
2023-11-06 secalert@redhat.com
6.6
CVSS 3.1 · NVD
View

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A07:2025 - Authentication Failures
ASVS 5.0
V6 - Authentication Authentication mechanism validation
MITRE ATT&CK

2 techniques across 2 tactics: Defense Evasion, Initial Access

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Impact

CVSS score of 6.6 (MEDIUM). Attack characteristics: physical attack vector, low complexity, no privileges required, user interaction required.

Exploit ScenarioDerived

An attacker could exploit this vulnerability to bypass authentication mechanisms to gain unauthorized access. No authentication is required to exploit this vulnerability.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
No patch listed yet 0.9% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAI

A flaw was found in OpenSC packages that allow a potential PIN bypass. Rated medium severity (CVSS 6.6), this vulnerability is no authentication required, low attack complexity. No vendor patch available.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Implement multi-factor authentication, enforce strong password policies, use proven authentication frameworks.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified as Improper Authentication (CWE-287), which allows attackers to bypass authentication mechanisms to gain unauthorized access. A flaw was found in OpenSC packages that allow a potential PIN bypass. When a token/card is authenticated by one process, it can perform cryptographic operations in other processes when an empty zero-length pin is passed. This issue poses a security risk, particularly for OS logon/screen unlock and for small, permanently connected tokens to computers. Additionally, the token can internally track login status. This flaw allows an attacker to gain unauthorized access, carry out malicious actions, or compromise the system without the user's awareness. Affected products include: Opensc Project Opensc, Redhat Enterprise Linux.

Know when Opensc gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

NVD PRIMARY 6.6 MEDIUM
AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Physical
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

DescriptionNVD

A flaw was found in OpenSC packages that allow a potential PIN bypass. When a token/card is authenticated by one process, it can perform cryptographic operations in other processes when an empty zero-length pin is passed. This issue poses a security risk, particularly for OS logon/screen unlock and for small, permanently connected tokens to computers. Additionally, the token can internally track login status. This flaw allows an attacker to gain unauthorized access, carry out malicious actions, or compromise the system without the user's awareness.

Threat Intelligence Overview

EPSS Score
0.9%
Top 44% exploitable
Data Quality
3 sources
Confidence: Low

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC No
EPSS 0.9%
Patch available No
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Defer
Exploitation· derived
None
System Exposure· derived
Small
Automatable· derived
No
Human Impact· derived
Medium

Priority Score

34
Low Medium High Critical
KEV: 0
EPSS: +1
CVSS: +33
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.

Affected Products (CPE)NVD

cpe:2.3:a:opensc_project:opensc:*:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*

More in Opensc

View all
CVE-2019-6502 HIGH POC
7.5 Jan 22

sc_context_create in ctx.c in libopensc in OpenSC 0.19.0 has a memory leak, as demonstrated by a call from eidenv. Rated

CVE-2018-16393 MEDIUM POC
6.8 Sep 03

Several buffer overflows when handling responses from a Gemsafe V1 Smartcard in gemsafe_get_cert_len in libopensc/pkcs15

CVE-2018-16392 MEDIUM POC
6.8 Sep 03

Several buffer overflows when handling responses from a TCOS Card in tcos_select_file in libopensc/card-tcos.c in OpenSC

CVE-2018-16391 MEDIUM POC
6.8 Sep 03

Several buffer overflows when handling responses from a Muscle Card in muscle_list_files in libopensc/card-muscle.c in O

CVE-2018-16425 MEDIUM POC
6.6 Sep 04

A double free when handling responses from an HSM Card in sc_pkcs15emu_sc_hsm_init in libopensc/pkcs15-sc-hsm.c in OpenS

CVE-2018-16424 MEDIUM POC
6.6 Sep 04

A double free when handling responses in read_file in tools/egk-tool.c (aka the eGK card tool) in OpenSC before 0.19.0-r

CVE-2018-16423 MEDIUM POC
6.6 Sep 04

A double free when handling responses from a smartcard in sc_file_set_sec_attr in libopensc/sc.c in OpenSC before 0.19.0

CVE-2018-16422 MEDIUM POC
6.6 Sep 04

A single byte buffer overflow when handling responses from an esteid Card in sc_pkcs15emu_esteid_init in libopensc/pkcs1

CVE-2018-16421 MEDIUM POC
6.6 Sep 04

Several buffer overflows when handling responses from a CAC Card in cac_get_serial_nr_from_CUID in libopensc/card-cac.c

CVE-2018-16420 MEDIUM POC
6.6 Sep 04

Several buffer overflows when handling responses from an ePass 2003 Card in decrypt_response in libopensc/card-epass2003

CVE-2018-16419 MEDIUM POC
6.6 Sep 04

Several buffer overflows when handling responses from a Cryptoflex card in read_public_key in tools/cryptoflex-tool.c in

CVE-2018-16418 MEDIUM POC
6.6 Sep 04

A buffer overflow when handling string concatenation in util_acl_to_str in tools/util.c in OpenSC before 0.19.0-rc1 coul

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy