What’s Vulnerable › Vulnerabilities

CVE-2019-19330

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 4.0% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2019-11-27 · updated 2026-06-17
• Weakness: CWE-74

Description

The HTTP/2 implementation in HAProxy before 2.0.10 mishandles headers, as demonstrated by carriage return (CR, ASCII 0xd), line feed (LF, ASCII 0xa), and the zero character (NUL, ASCII 0x0), aka Intermediary Encapsulation Attacks.

Affected products

• Canonical Ubuntu Linux: 18.04, 19.04, 19.10
• Debian Linux: 10.0
• HAProxy: before 2.0.10 — fixed in 2.0.10

How to fix

Upgrade to a fixed version: HAProxy 2.0.10. Check the vendor advisory for mitigations.

References

• https://git.haproxy.org/?p=haproxy-2.0.git%3Ba=commit%3Bh=ac198b92d461515551b95daae20954b3053ce87e
• https://git.haproxy.org/?p=haproxy.git%3Ba=commit%3Bh=146f53ae7e97dbfe496d0445c2802dd0a30b0878
• https://git.haproxy.org/?p=haproxy.git%3Ba=commit%3Bh=54f53ef7ce4102be596130b44c768d1818570344
• https://seclists.org/bugtraq/2019/Nov/45
• https://security.gentoo.org/glsa/202004-01
• https://tools.ietf.org/html/rfc7540#section-10.3
• https://usn.ubuntu.com/4212-1/
• https://www.debian.org/security/2019/dsa-4577
• https://git.haproxy.org/?p=haproxy-2.0.git%3Ba=commit%3Bh=ac198b92d461515551b95daae20954b3053ce87e
• https://git.haproxy.org/?p=haproxy.git%3Ba=commit%3Bh=146f53ae7e97dbfe496d0445c2802dd0a30b0878
• https://git.haproxy.org/?p=haproxy.git%3Ba=commit%3Bh=54f53ef7ce4102be596130b44c768d1818570344
• https://seclists.org/bugtraq/2019/Nov/45

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