UpHeron
All vulnerabilities

Servers and applications

CVE-2021-40346

An integer overflow exists in HAProxy 2.0 through 2.5 in htx_add_header that can be exploited to perform an HTTP request smuggling attack, allowing an attacker to bypass all configured http-request HAProxy ACLs and possibly other ACLs.

Severity
High 7.5
Published
8 Sept 2021
Last changed
17 Jun 2026
Added to UpHeron
21 Oct 2026
Fixed in
2.0.25, 2.2.17, 2.3.14, 2.4.4
Sources
NVD

Affected software

SoftwareAffected versions
HAProxyServers and applications · cpe:a:haproxy:haproxy
  • Version 2.5-dev6
  • Version 2.5-dev5
  • Version 2.5-dev4
  • Version 2.5-dev3
All 11 release lines
  • From 2.0.0 before 2.0.25
  • From 2.2.0 before 2.2.17
  • From 2.3.0 before 2.3.14
  • From 2.4.0 before 2.4.4
  • Version 2.5-dev0
  • Version 2.5-dev1
  • Version 2.5-dev2
  • Version 2.5-dev3
  • Version 2.5-dev4
  • Version 2.5-dev5
  • Version 2.5-dev6

References

  • NVD https://nvd.nist.gov/vuln/detail/CVE-2021-40346
  • CVE.org https://www.cve.org/CVERecord?id=CVE-2021-40346