CVE-1999-1199: Critical severity Apache HTTP Server vulnerability
Apache WWW server 1.3.1 and earlier allows remote attackers to cause a denial of service (resource exhaustion) via a large number of MIME headers with the same name, aka the "sioux" vulnerability.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
Deploy a front-end filter (WAF, proxy or firewall) to detect and drop or rate-limit requests that contain excessive numbers of identical MIME headers to mitigate resource-exhaustion attacks.
- Operational
Enable logging and monitor for requests with large numbers of duplicate MIME headers; if resource exhaustion is observed, restart affected HTTP server processes and block or throttle offending source IPs while applying a permanent fix.
Event History
Frequently Asked Questions
What is the severity of CVE-1999-1199?
CVE-1999-1199 is classified as a denial of service vulnerability, which can lead to resource exhaustion on Apache servers.
How does CVE-1999-1199 affect the Apache HTTP Server?
CVE-1999-1199 allows remote attackers to exhaust server resources by sending a large number of MIME headers with the same name.
What versions of Apache are vulnerable to CVE-1999-1199?
CVE-1999-1199 affects Apache HTTP Server versions 1.3.1 and earlier.
How can I mitigate the effects of CVE-1999-1199?
To mitigate CVE-1999-1199, users should upgrade to a patched version of Apache HTTP Server that is not affected by this vulnerability.
Is there a workaround for CVE-1999-1199 until I can upgrade?
As a temporary workaround for CVE-1999-1199, consider limiting the number of MIME headers accepted by the server configuration.