CVE-2019-0197: mod_http2, possible crash on late upgrade

[Daniel Ruggeri <druggeri () apache org>]

CVE-2019-0197: mod_http2, possible crash on late upgrade

Severity: Low

Vendor: The Apache Software Foundation

Versions Affected:
httpd 2.4.34 to 2.4.38

Description:
When HTTP/2 was enabled for a http: host or H2Upgrade was enabled for h2
on a https: host, an Upgrade request from http/1.1 to http/2 that was
not the first request on a connection could lead to a misconfiguration
and crash. Servers that never enabled the h2 protocol or only enabled it
for https: and did not set"H2Upgrade on" are unaffected by this issue.

Mitigation:
All httpd users deploying mod_http2 should upgrade to 2.4.39 or later.

Credit:
The issue was discovered by Stefan Eissing, greenbytes.de.

References:
https://httpd.apache.org/security/vulnerabilities_24.html