OpenSSL Fixes Multiple New Security Flaws with Latest Update

Feb 09, 2023Ravie LakshmananEncryption / Vulnerability

The OpenSSL Project has released fixes to address several
security flaws, including a high-severity bug in the open source
encryption toolkit that could potentially expose users to malicious
attacks.

Tracked as CVE-2023-0286^[1], the issue relates to a
case of type confusion that may permit an adversary to “read memory
contents or enact a denial-of-service,” the maintainers said in an
advisory.

The vulnerability is rooted in the way the popular cryptographic library^[2] handles X.509
certificates, and is likely to impact only those applications that
have a custom implementation for retrieving a certificate
revocation list (CRL^[3]) over a network.

“In most cases, the attack requires the attacker to provide both
the certificate chain and CRL, neither of which need to have a
valid signature,” OpenSSL said^[4]. “If the attacker only
controls one of these inputs, the other input must already contain
an X.400 address as a CRL distribution point, which is
uncommon.”

Type confusion flaws could have serious consequences^[5], as they could be
weaponized to deliberately force the program to behave in
unintended ways, possibly causing a crash or code execution.

The issue has been patched in OpenSSL versions 3.0.8, 1.1.1t,
and 1.0.2zg. Other security flaws addressed^[6]
as part of the latest updates include:

• CVE-2022-4203 – X.509 Name Constraints Read
  Buffer Overflow
• CVE-2022-4304 – Timing Oracle in RSA
  Decryption
• CVE-2022-4450 – Double free after calling
  PEM_read_bio_ex
• CVE-2023-0215 – Use-after-free following
  BIO_new_NDEF
• CVE-2023-0216 – Invalid pointer dereference in
  d2i_PKCS7 functions
• CVE-2023-0217 – NULL dereference validating
  DSA public key
• CVE-2023-0401 – NULL dereference during PKCS7
  data verification

Successful exploitation of the above shortcomings could lead to
an application crash, disclose memory contents, and even recover
plaintext messages sent over a network by taking advantage of a
timing-based side-channel^[7] in what’s a Bleichenbacher-style attack^[8].

The fixes arrive nearly two months after OpenSSL plugged a
low-severity flaw (CVE-2022-3996^[9]) that arises when
processing an X.509 certificate, resulting in a denial-of-service
condition.