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

*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.

*Credits: N/A

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
2024-07-17 EPSS Updated
2024-08-04 CVE 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 (16)

URL	Tag	Source
https://lists.apache.org/thread.html/r284567dd7523f5823e2ce995f787ccd37b1cc4108779c50a97c79120%40%3Cdev.cloudstack.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/r8a58fd7a29808e5d27ee56877745e58dc4bb041b9af94601554e2a5a%40%3Cdev.cloudstack.apache.org%3E	Mailing List
https://www.mail-archive.com/haproxy%40formilux.org	X_refsource_misc
https://www.mail-archive.com/haproxy%40formilux.org/msg41114.html	X_refsource_misc

URL	Date	SRC
https://github.com/knqyf263/CVE-2021-40346	2021-09-08
https://github.com/donky16/CVE-2021-40346-POC	2021-09-28
https://github.com/alikarimi999/CVE-2021-40346	2021-09-13
https://github.com/alexOarga/CVE-2021-40346	2022-01-24
https://jfrog.com/blog/critical-vulnerability-in-haproxy-cve-2021-40346-integer-overflow-enables-http-smuggling	2024-08-04

URL	Date	SRC
https://git.haproxy.org/?p=haproxy.git	2023-11-07
https://github.com/haproxy/haproxy/commit/3b69886f7dcc3cfb3d166309018e6cfec9ce2c95	2023-11-07

URL	Date	SRC
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A7V2IYO22LWVBGUNZWVKNTMDV4KINLFO	2023-11-07
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MXTSBY2TEAXWZVFQM3CXHJFRONX7PEMN	2023-11-07
https://www.debian.org/security/2021/dsa-4968	2023-11-07
https://access.redhat.com/security/cve/CVE-2021-40346	2022-01-19
https://bugzilla.redhat.com/show_bug.cgi?id=2000599	2022-01-19

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