Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to versions 6.0.16 and 7.0.3, an attacker can craft traffic to cause Suricata to use far more CPU and memory for processing the traffic than needed, which can lead to extreme slow downs and denial of service. This vulnerability is patched in 6.0.16 or 7.0.3. Workarounds include disabling the affected protocol app-layer parser in the yaml and reducing the `stream.reassembly.depth` value helps reduce the severity of the issue.
In Suricata before 6.0.13 (when there is an adversary who controls an external source of rules), a dataset filename, that comes from a rule, may trigger absolute or relative directory traversal, and lead to write access to a local filesystem. This is addressed in 6.0.13 by requiring allow-absolute-filenames and allow-write (in the datasets rules configuration section) if an installation requires traversal/writing in this situation.
In Suricata before 6.0.13, an adversary who controls an external source of Lua rules may be able to execute Lua code. This is addressed in 6.0.13 by disabling Lua unless allow-rules is true in the security lua configuration section.
An issue was discovered in Suricata before 6.0.4. It is possible to bypass/evade any HTTP-based signature by faking an RST TCP packet with random TCP options of the md5header from the client side. After the three-way handshake, it's possible to inject an RST ACK with a random TCP md5header option. Then, the client can send an HTTP GET request with a forbidden URL. The server will ignore the RST ACK and send the response HTTP packet for the client's request. These packets will not trigger a Suricata reject action.
Open Information Security Foundation Suricata prior to version 4.1.3 is affected by: Denial of Service - TCP/HTTP detection bypass. The impact is: An attacker can evade a signature detection with a specialy formed sequence of network packets. The component is: detect.c (https://github.com/OISF/suricata/pull/3625/commits/d8634daf74c882356659addb65fb142b738a186b). The attack vector is: An attacker can trigger the vulnerability by a specifically crafted network TCP session. The fixed version is: 4.1.3.