CVE-2021-40346

HIGHScheduled

Published:Sep 8, 2021(4 years ago)

Modified:Nov 21, 2024

Remote ExploitNo Auth RequiredNo InteractionLow Complexity

Vulnerability Description

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.

Attack Characteristics

Network AccessLow ComplexityNo Auth NeededNo User Interaction

🤖

AI analysis not yet available

Plain-English explanation, risk summary, and remediation steps will appear here once AI analysis is complete.

No Fix Known

No patch has been released yet. Apply workarounds or mitigations where available.

Affected Software

Vendor	Product	Versions	Fixed In
haproxy	haproxy	2.0.0 - 2.0.25	-
haproxy	haproxy	2.2.0 - 2.2.17	-
haproxy	haproxy	2.3.0 - 2.3.14

Timeline

Published
CVE disclosed publicly
Sep 8, 20214 years ago
Last Modified
Most recent update
Nov 21, 20241 year ago
Indexed to CVEInsight
Added to this platform
Mar 29, 20261 month ago

References

https://git.haproxy.org/?p=haproxy.gitPatch
https://github.com/haproxy/haproxy/commit/3b69886f7dcc3cfb3d166309018e...Patch
https://jfrog.com/blog/critical-vulnerability-in-haproxy-cve-2021-4034...Exploit

CVSS Score

v3.1

7.5/ 10.0

HIGH

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

At a Glance

Affected Products

References

haproxy / haproxy

https://lists.apache.org/thread.html/r284567dd7523f5823e2ce995f787ccd3...

https://lists.apache.org/thread.html/r8a58fd7a29808e5d27ee56877745e58d...

https://lists.fedoraproject.org/archives/list/package-announce%40lists...

https://www.debian.org/security/2021/dsa-4968Third Party Advisory

https://www.mail-archive.com/haproxy%40formilux.org

https://www.mail-archive.com/haproxy%40formilux.org/msg41114.html

https://git.haproxy.org/?p=haproxy.gitPatch

https://github.com/haproxy/haproxy/commit/3b69886f7dcc3cfb3d166309018e...Patch

https://jfrog.com/blog/critical-vulnerability-in-haproxy-cve-2021-4034...Exploit

https://lists.apache.org/thread.html/r284567dd7523f5823e2ce995f787ccd3...

https://lists.apache.org/thread.html/r8a58fd7a29808e5d27ee56877745e58d...

https://lists.fedoraproject.org/archives/list/package-announce%40lists...

https://www.debian.org/security/2021/dsa-4968Third Party Advisory

https://www.mail-archive.com/haproxy%40formilux.org

https://www.mail-archive.com/haproxy%40formilux.org/msg41114.html

CVSS v3 Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

Impact

ScopeUnchanged

ConfidentialityNone

IntegrityHigh

AvailabilityNone

Impact Analysis

ConfidentialityNone

NoneLowHigh

IntegrityHigh

NoneLowHigh

AvailabilityNone

NoneLowHigh

CVE-2021-40346

✦ Vulnerability Description

Attack Characteristics

Affected Software

Timeline

References

CVSS Score

At a Glance

Official Sources

CVSS v3 Vector

Impact Analysis

Vulnerability Description