CVE-2021-40346

HIGH severity · CVSS 7.5 · Integer overflow

7.5CVSS HIGH

Summary

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.

Impact & exploitability

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

Confidentiality impactNone

Integrity impactHigh

Availability impactNone

Exploit probability (EPSS)92%

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

Affected products we track (1)

HAProxy

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

Official patch: https://git.haproxy.org/?p=haproxy.git ↗

Additional information

NVD record
https://git.haproxy.org/?p=haproxy.gitPatch
https://github.com/haproxy/haproxy/commit/3b69886f7dcc3cfb3d166309018e6cfec9ce2c95Patch
https://jfrog.com/blog/critical-vulnerability-in-haproxy-cve-2021-40346-integer-overflow-enables-http-smuggling/Advisory
https://lists.apache.org/thread.html/r284567dd7523f5823e2ce995f787ccd37b1cc4108779c50a97c79120%40%3Cdev.cloudstack.apache.org%3E
https://lists.apache.org/thread.html/r8a58fd7a29808e5d27ee56877745e58dc4bb041b9af94601554e2a5a%40%3Cdev.cloudstack.apache.org%3E
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A7V2IYO22LWVBGUNZWVKNTMDV4KINLFO/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MXTSBY2TEAXWZVFQM3CXHJFRONX7PEMN/
https://www.debian.org/security/2021/dsa-4968Advisory