Vulnerability in Haproxy

CVE-2021-39240

An issue was discovered in HAProxy 2.2 before 2.2.16, 2.3 before 2.3.13, and 2.4 before 2.4.3. It does not ensure that the scheme and path portions of a URI have the expected characters. For example, the authority field (as observed on a target HTTP/2 server) might differ from what the routing rules were intended to achieve.

EPSS: 0.023 (81.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

Affected products

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-39240?
CVE-2021-39240 is a high-severity vulnerability in Haproxy. CVSS score: 7.5/10. Published 2021-08-17.
How severe is CVE-2021-39240?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2021-39240 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.