When RSASSA-PSS signature verification is enabled, sending a maliciously constructed certificate chain can be used to cause a buffer overflow on the peer's stack, potentially leading to crash or remote code execution. This can be triggered remotely from either side in both TLS and DTLS.
RSASSA-PSS is the part of PKCS #1 v2.1 standard and can be enabled by the compile time option MBEDTLS_PKCS1_V21 in config.h. If MBEDTLS_PKCS1_V21 is disabled when compiling the library, then the vulnerability is not present. RSASSA-PSS signatures are enabled in the default configuration.
Affected versions: all versions of Mbed TLS from version 1.3.8 and up, including all 2.1 and later releases
Created mbedtls tracking bugs for this issue:
Affects: epel-all [bug 1544730]
Affects: fedora-all [bug 1544729]
This CVE Bugzilla entry is for community support informational purposes only as it does not affect a package in a commercially supported Red Hat product. Refer to the dependent bugs for status of those individual community products.