wolfSSL Release 5.5.0 Vulnerabilities

wolfSSL release 5.5.0 contained 4 vulnerability fixes. Most are considered low severity and affect a very small subset of users. 3 of the listed issues were found by external researchers (thanks to their efforts! you can see them mentioned on each of the reports) The last one listed with a potential DTLS DoS attack was found thanks to our internal testing.

CVE ID Severity Description
CVE-2022-38153 Low In wolfSSL version 5.3.0 if compiled with –enable-session-ticket and the client has non-empty session cache, with TLS 1.2 there is the possibility of a man in the middle passing a large session ticket to the client and causing a crash due to an invalid free. There is also the potential for a malicious TLS 1.3 server to crash a client in a similar manner except in TLS 1.3 it is not susceptible to a man in the middle attack. Users on the client side with –enable-session-ticket compiled in and using wolfSSL version 5.3.0 should update their version of wolfSSL. 

Thanks to Max at Trail of Bits for the report and “LORIA, INRIA, France” for research on tlspuffin.

CVE-2022-38152 Low If using wolfSSL_clear to reset a WOLFSSL object (vs the normal wolfSSL_free/wolfSSL_new) it can result in runtime issues. This exists with builds using the wolfSSL compatibility layer (–enable-opnesslextra) and only when the application is making use of wolfSSL_clear instead of SSL_free/SSL_new. In the case of a TLS 1.3 resumption, after continuing to use the WOLFSSH object after having called wolfSSL_clear, an application could crash. It is suggested that users calling wolfSSL_clear update the version of wolfSSL used. 

Thanks to Max at Trail of Bits for the report and “LORIA, INRIA, France” for research on tlspuffin.

N/A Low Fault injection attack on RAM via Rowhammer leads to ECDSA key disclosure. Users doing operations with private ECC keys such as server side TLS connections and creating ECC signatures, who also have hardware that could be targeted with a sophisticated Rowhammer attack should update the version of wolfSSL and compile using the macro WOLFSSL_CHECK_SIG_FAULTS. 

Thanks to Yarkin Doroz, Berk Sunar, Koksal Must, Caner Tol, and Kristi Rahman all affiliated with the Vernam Applied Cryptography and Cybersecurity Lab at Worcester Polytechnic Institute for the report.

N/A Medium Potential DoS attack on DTLS 1.2. In the case of receiving a malicious plaintext handshake message at epoch 0 the connection will enter an error state reporting a duplicate message. This affects both server and client side. Users that have DTLS enabled and in use should update their version of wolfSSL to mitigate the potential for a DoS attack.


If not free’ing FP_ECC caches per thread by calling wc_ecc_fp_free there is a possible memory leak during TLS 1.3 handshakes which use ECC. Users are urged to confirm they are free’ing FP_ECC caches per thread if enabled to avoid this issue. 


For additional vulnerability information visit the vulnerability page at https://www.wolfssl.com/docs/security-vulnerabilities/

A full list of what was changed can be found in the wolfSSL ChangeLog (https://www.wolfssl.com/docs/wolfssl-changelog/).

If you have a vulnerability to report or would like more information, contact us at facts@wolfssl.com, the wolfSSL development team takes vulnerabilities seriously.