Mailing List Archive

CVE-2018-1283: Tampering of mod_session data for CGI applications
CVE-2018-1283: Tampering of mod_session data for CGI applications.

Severity: Medium

Vendor: The Apache Software Foundation

Versions Affected:
httpd 2.4.0 to 2.4.29

Description:

When mod_session is configured to forward its session data to CGI
applications (SessionEnv on, not the default), a remote user may influence
their content by using a "Session" header. This comes from the "HTTP_SESSION"
variable name used by mod_session to forward its data to CGIs, since the
prefix "HTTP_" is also used by the Apache HTTP Server to pass HTTP header
fields, per CGI specifications.

The severity is set to Medium because "SessionEnv on" is not a default nor
common configuration, it should be considered High when this is the case
though, because of the possible remote exploitation.

Mitigation:
All httpd users should upgrade to 2.4.30 or later.

Credit:
The issue was discovered internally by the Apache HTTP Server team.

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