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.

The remote Debian 11 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-4103 advisory.

    - -------------------------------------------------------------------------     Debian LTS Advisory DLA-4103-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                    Thorsten Alteholz     March 31, 2025                                https://wiki.debian.org/LTS
    - -------------------------------------------------------------------------

    Package        : suricata     Version        : 1:6.0.1-3+deb11u1     CVE ID         : CVE-2021-45098 CVE-2023-35852 CVE-2024-32663                      CVE-2024-37151 CVE-2024-45796 CVE-2024-55626                      CVE-2025-29918


    Several issues have been found in suricata, the next Generation Intrusion     Detection and Prevention Tool. They are related to bypass of HTTP-based     signature, mishandling of multiple fragmented packets, logic errors,     infinite loops, buffer overflows, unintended file access and using large     amount of memory.



    For Debian 11 bullseye, these problems have been fixed in version     1:6.0.1-3+deb11u1.

    We recommend that you upgrade your suricata packages.

    For the detailed security status of suricata please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/suricata

    Further information about Debian LTS security advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://wiki.debian.org/LTS

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

  - Suricata before 5.0.8 and 6.x before 6.0.4 allows TCP evasion via a client with a crafted TCP/IP stack
    that can send a certain sequence of segments. (CVE-2021-37592)

  - 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.
    (CVE-2021-45098)

ID	Name	Product	Family	Severity
233594	Debian dla-4103 : suricata - security update	Nessus	Debian Local Security Checks	high
407295	Alpine: multiple suricata packages: security update to 6.0.4-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	critical
407295	Alpine: multiple suricata packages: security update to 6.0.4-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	critical

Detections

Analytics

CVE-2021-45098

high

Tenable Plugins

high

critical

critical