CVE-2021-40346
7.5 HIGHAn 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...
Published: 2021-09-08 · Last updated: 2026-06-17
Severity and scoring
- CVSS
- 7.5 HIGH
- Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- CWE
- CWE-190
Affected products
| Vendor | Product |
|---|---|
| debian | debian_linux, fedora, haproxy |
| fedoraproject | debian_linux, fedora, haproxy |
| haproxy | debian_linux, fedora, haproxy |
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.
Source: NVD
References
- [NVD]https://nvd.nist.gov/vuln/detail/CVE-2021-40346
- [Patch]https://git.haproxy.org/?p=haproxy.git
- [Patch]https://github.com/haproxy/haproxy/commit/3b69886f7dcc3cfb3d166309018e6cfec9ce2c95
- [Exploit reference]https://jfrog.com/blog/critical-vulnerability-in-haproxy-cve-2021-40346-integer-overflow-enables-http-smuggling/
- [Other]https://lists.apache.org/thread.html/r284567dd7523f5823e2ce995f787ccd37b1cc4108779c50a97c79120%40%3Cdev.cloudstack.apache.org%3E
- [Other]https://lists.apache.org/thread.html/r8a58fd7a29808e5d27ee56877745e58dc4bb041b9af94601554e2a5a%40%3Cdev.cloudstack.apache.org%3E
- [Other]https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A7V2IYO22LWVBGUNZWVKNTMDV4KINLFO/
- [Other]https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MXTSBY2TEAXWZVFQM3CXHJFRONX7PEMN/
- [Other]https://www.debian.org/security/2021/dsa-4968
- [Other]https://www.mail-archive.com/haproxy%40formilux.org
- [Other]https://www.mail-archive.com/haproxy%40formilux.org/msg41114.html
- [Patch]https://git.haproxy.org/?p=haproxy.git
- [Patch]https://github.com/haproxy/haproxy/commit/3b69886f7dcc3cfb3d166309018e6cfec9ce2c95
- [Exploit reference]https://jfrog.com/blog/critical-vulnerability-in-haproxy-cve-2021-40346-integer-overflow-enables-http-smuggling/
- [Other]https://lists.apache.org/thread.html/r284567dd7523f5823e2ce995f787ccd37b1cc4108779c50a97c79120%40%3Cdev.cloudstack.apache.org%3E
- [Other]https://lists.apache.org/thread.html/r8a58fd7a29808e5d27ee56877745e58dc4bb041b9af94601554e2a5a%40%3Cdev.cloudstack.apache.org%3E
- [Other]https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A7V2IYO22LWVBGUNZWVKNTMDV4KINLFO/
- [Other]https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MXTSBY2TEAXWZVFQM3CXHJFRONX7PEMN/
- [Other]https://www.debian.org/security/2021/dsa-4968
- [Other]https://www.mail-archive.com/haproxy%40formilux.org
- [Other]https://www.mail-archive.com/haproxy%40formilux.org/msg41114.html
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