CVE-2021-45098
mediumpriority · track · 31OT risk · elevatedEPSS 0.020 · 80 %ileEURUUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5–7.5
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (9)
Products and version ranges known to be affected.
also known as (4)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (15)
External citations — patches, advisories, analysis.
- https://forum.suricata.io/t/suricata-6-0-4-and-5-0-8-released/1942cnnvd
- https://github.com/OISF/suricata/commit/50e2b973eeec7172991bf8f544ab06fb782b97dfcnnvd
- https://github.com/OISF/suricata/releasescnnvd
- https://github.com/OISF/suricata。Patchcnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2021-45098cnnvd
- https://redmine.openinfosecfoundation.org/issues/4710cnnvd
- https://forum.suricata.io/t/suricata-6-0-4-and-5-0-8-released/1942enisa_euvd
- https://github.com/OISF/suricata/commit/50e2b973eeec7172991bf8f544ab06fb782b97dfenisa_euvd
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