An integer underflow issue exists in wolfSSL when parsing the Subject Alternative Name (SAN) extension of X.509 certificates. A malformed certificate can specify an entry length larger than the enclosing sequence, causing the internal length counter to wrap during parsing. This results in incorrect handling of certificate data.
The issue is limited to configurations using the original ASN.1 parsing implementation which is off by default.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Attack Requirements
Present
Additional conditions required
Privileges Required
None
No privileges needed
User Interaction
Passive
Minimal interaction
Impact Assessment
Confidentiality
Low
Partial data leak
Integrity
None
No data modification
Availability
Low
Partial disruption
CVSS Vector v4.0