Crypt::OpenSSL::X509 versions before 2.1.3 for Perl allow a heap out-of-bounds read via a long certificate extension OID in hv_exts.
When building the extension hash (via extensions(), extensions_by_long_name(), extensions_by_oid(), or has_extension_oid()), the code passes OBJ_obj2txt()'s return value as the hash-key length; because that value is the OID's full text length rather than the bytes written to the fixed-size buffer (129 bytes), an OID whose text is longer than the 129-byte buffer causes a read past the allocation, exposing adjacent heap memory as the returned hash key. extensions_by_name() uses the static shortname path and is not affected.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
Weakness Type (CWE)
Vulnerable Products 1
| Configuration | From (including) | Up to (excluding) |
|---|---|---|
|
Jonasbn Crypt\
cpe:2.3:a:jonasbn:crypt\:\:openssl\:\:x509:*:*:*:*:*:perl:*:*
|
— |
2.1.3
|