Picotls
Monthly
A NULL-pointer dereference in the picotls TLS 1.3 library crashes any process that uses picotls as its client-side TLS stack when a malicious or man-in-the-middle peer answers a handshake with a HelloRetryRequest followed by a spoofed Hello message. Only builds up to and including revision 44bc503 are affected; the flaw is fixed in commit a06ca41. Impact is availability-only (process termination, no code execution or data disclosure), and the client must be induced to connect to the hostile peer, which is why the assessed vector carries a user-interaction requirement. No public exploit code and no confirmed active exploitation were identified at time of analysis.
Stack exhaustion in the Picotls minicrypto backend's custom ASN.1 validator allows an attacker who can supply crafted private-key material to crash any application that calls ptls_minicrypto_load_private_key() or the public ptls_asn1_validation() API on untrusted DER input. All Picotls versions prior to upstream commit c14231d80 are affected when the minicrypto backend is in use; applications using the libcrypto (OpenSSL) backend are immune because OpenSSL performs its own bounded DER parsing. No public exploit has been identified and no CISA KEV listing exists; CVSS 5.5 reflects a local, user-interaction-dependent denial-of-service with no code execution potential.
Picotls is a TLS protocol library that allows users select different crypto backends based on their use case. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
A NULL-pointer dereference in the picotls TLS 1.3 library crashes any process that uses picotls as its client-side TLS stack when a malicious or man-in-the-middle peer answers a handshake with a HelloRetryRequest followed by a spoofed Hello message. Only builds up to and including revision 44bc503 are affected; the flaw is fixed in commit a06ca41. Impact is availability-only (process termination, no code execution or data disclosure), and the client must be induced to connect to the hostile peer, which is why the assessed vector carries a user-interaction requirement. No public exploit code and no confirmed active exploitation were identified at time of analysis.
Stack exhaustion in the Picotls minicrypto backend's custom ASN.1 validator allows an attacker who can supply crafted private-key material to crash any application that calls ptls_minicrypto_load_private_key() or the public ptls_asn1_validation() API on untrusted DER input. All Picotls versions prior to upstream commit c14231d80 are affected when the minicrypto backend is in use; applications using the libcrypto (OpenSSL) backend are immune because OpenSSL performs its own bounded DER parsing. No public exploit has been identified and no CISA KEV listing exists; CVSS 5.5 reflects a local, user-interaction-dependent denial-of-service with no code execution potential.
Picotls is a TLS protocol library that allows users select different crypto backends based on their use case. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.