CVE-2021-40346

high-risk
Published 2021-09-08

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.

Do I need to act?

!
92.4% chance of exploitation in next 30 days
EPSS score — higher than 8% of all CVEs
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
7
CVSS 7.5/10 High
NETWORK / LOW complexity

Affected Vendors

References (20)

62
/ 100
high-risk
Severity 26/34 · High
Exploitability 20/34 · Moderate
Exposure 16/34 · Moderate