DescriptionAn issue was discovered in wolfSSL before 5.5.0 (when --enable-session-ticket is used); however, only version 5.3.0 is exploitable. Man-in-the-middle attackers or a malicious server can crash TLS 1.2 clients during a handshake. If an attacker injects a large ticket (more than 256 bytes) into a NewSessionTicket message in a TLS 1.2 handshake, and the client has a non-empty session cache, the session cache frees a pointer that points to unallocated memory, causing the client to crash with a "free(): invalid pointer" message. NOTE: It is likely that this is also exploitable during TLS 1.3 handshakes between a client and a malicious server. With TLS 1.3, it is not possible to exploit this as a man-in-the-middle.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs1021021

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
wolfssl (PTS)bullseye4.6.0+p1-0+deb11u2fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
wolfsslsourcebullseye(not affected)


[bullseye] - wolfssl <not-affected> (Vulnerable code not present and session tickets not enabled)

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