// For flags

CVE-2021-40346

haproxy: request smuggling attack or response splitting via duplicate content-length header

Severity Score

7.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

6
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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.

Se presenta un desbordamiento de enteros en HAProxy versiones 2.0 a 2.5, en la función htx_add_header() que puede ser explotada para llevar a cabo un ataque de contrabando de peticiones HTTP, permitiendo a un atacante omitir todas las ACLs configuradas de HAProxy de peticiones http y posiblemente otras ACLs

Proxy server haproxy has a flaw that can could allow an HTTP request smuggling attack with the goal of bypassing access-control list rules defined by haproxy. The attack was made possible by utilizing an integer overflow vulnerability that allowed reaching an unexpected state in haproxy while parsing an HTTP request. The highest threat from this vulnerability is integrity.

Red Hat Advanced Cluster Management for Kubernetes 2.2.11 images Red Hat Advanced Cluster Management for Kubernetes provides the capabilities to address common challenges that administrators and site reliability engineers face as they work across a range of public and private cloud environments. Clusters and applications are all visible and managed from a single console — with security policy built in. This advisory contains the container images for Red Hat Advanced Cluster Management for Kubernetes, which provide security fixes, bug fixes and container upgrades. Issues addressed include a bypass vulnerability.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
None
Integrity
Partial
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-08-31 CVE Reserved
  • 2021-09-08 CVE Published
  • 2021-09-08 First Exploit
  • 2024-08-04 CVE Updated
  • 2025-04-01 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
CWE
  • CWE-190: Integer Overflow or Wraparound
  • CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
CAPEC
References (17)
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Haproxy
Search vendor "Haproxy"
Haproxy
Search vendor "Haproxy" for product "Haproxy"
>= 2.0.0 < 2.0.25
Search vendor "Haproxy" for product "Haproxy" and version " >= 2.0.0 < 2.0.25"
-
Affected
Haproxy
Search vendor "Haproxy"
Haproxy
Search vendor "Haproxy" for product "Haproxy"
>= 2.2.0 < 2.2.17
Search vendor "Haproxy" for product "Haproxy" and version " >= 2.2.0 < 2.2.17"
-
Affected
Haproxy
Search vendor "Haproxy"
Haproxy
Search vendor "Haproxy" for product "Haproxy"
>= 2.3.0 < 2.3.14
Search vendor "Haproxy" for product "Haproxy" and version " >= 2.3.0 < 2.3.14"
-
Affected
Haproxy
Search vendor "Haproxy"
Haproxy
Search vendor "Haproxy" for product "Haproxy"
>= 2.4.0 < 2.4.4
Search vendor "Haproxy" for product "Haproxy" and version " >= 2.4.0 < 2.4.4"
-
Affected
Haproxy
Search vendor "Haproxy"
Haproxy
Search vendor "Haproxy" for product "Haproxy"
2.5
Search vendor "Haproxy" for product "Haproxy" and version "2.5"
dev0
Affected
Haproxy
Search vendor "Haproxy"
Haproxy
Search vendor "Haproxy" for product "Haproxy"
2.5
Search vendor "Haproxy" for product "Haproxy" and version "2.5"
dev1
Affected
Haproxy
Search vendor "Haproxy"
Haproxy
Search vendor "Haproxy" for product "Haproxy"
2.5
Search vendor "Haproxy" for product "Haproxy" and version "2.5"
dev2
Affected
Haproxy
Search vendor "Haproxy"
Haproxy
Search vendor "Haproxy" for product "Haproxy"
2.5
Search vendor "Haproxy" for product "Haproxy" and version "2.5"
dev3
Affected
Haproxy
Search vendor "Haproxy"
Haproxy
Search vendor "Haproxy" for product "Haproxy"
2.5
Search vendor "Haproxy" for product "Haproxy" and version "2.5"
dev4
Affected
Haproxy
Search vendor "Haproxy"
Haproxy
Search vendor "Haproxy" for product "Haproxy"
2.5
Search vendor "Haproxy" for product "Haproxy" and version "2.5"
dev5
Affected
Haproxy
Search vendor "Haproxy"
Haproxy
Search vendor "Haproxy" for product "Haproxy"
2.5
Search vendor "Haproxy" for product "Haproxy" and version "2.5"
dev6
Affected
Debian
Search vendor "Debian"
Debian Linux
Search vendor "Debian" for product "Debian Linux"
11.0
Search vendor "Debian" for product "Debian Linux" and version "11.0"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
Fedora
Search vendor "Fedoraproject" for product "Fedora"
33
Search vendor "Fedoraproject" for product "Fedora" and version "33"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
Fedora
Search vendor "Fedoraproject" for product "Fedora"
34
Search vendor "Fedoraproject" for product "Fedora" and version "34"
-
Affected