HAProxy is a TCP/HTTP reverse proxy for high availability environments.
It was discovered that HAProxy incorrectly handled certain HTTP/2 headers.
A remote attacker could send a specially crafted HTTP/2 header, possibly resulting in execution of arbitrary code with the privileges of the process or a Denial of Service condition.
There is no known workaround at this time.
All HAProxy 1.8.x users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-proxy/haproxy-1.8.23"
All HAProxy 1.9.x users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-proxy/haproxy-1.9.13"
All HAProxy 2.0.x users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-proxy/haproxy-2.0.10"