Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to 7.0.5 and 6.0.19, specially crafted traffic or datasets can cause a limited buffer overflow. This vulnerability is fixed in 7.0.5 and 6.0.19. Workarounds include not use rules with `base64_decode` keyword with `bytes` option with value 1, 2 or 5 and for 7.0.x, setting `app-layer.protocols.smtp.mime.body-md5` to false.
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow.