Bug 84642
| Summary: | passthru() causes DoS | ||
|---|---|---|---|
| Product: | [Retired] Red Hat Linux | Reporter: | Gigs <jgiglio> |
| Component: | httpd | Assignee: | Joe Orton <jorton> |
| Status: | CLOSED DUPLICATE | QA Contact: | David Lawrence <dkl> |
| Severity: | medium | Docs Contact: | |
| Priority: | high | ||
| Version: | 8.0 | Keywords: | Security |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2006-02-21 18:51:53 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
passthru() did get optimized recently upstream, though this sounds like a more serious problem. (http://bugs.php.net/bug.php?id=22308) This was a problem where httpd would sometimes buffer up dynamic content, and was fixed by the most recent httpd erratum. Thanks for the report. *** This bug has been marked as a duplicate of 97111 *** Changed to 'CLOSED' state since 'RESOLVED' has been deprecated. |
Description of problem: PHP's passthru function in Red Hat 8 stock PHP/Apache2 is barely functional, if the program it runs returns any significant amount of data, it causes a DoS situation, the server will become very unresponsive, and the query takes much longer than expected. This could be remotely exploited as a system-wide DoS attack if the user has any script that uses a passthru() function to return data the user requested from an external command. Version-Release number of selected component (if applicable): php-4.2.2-8.0.7 httpd-2.0.40-11 How reproducible: Always Steps to Reproduce: 1. Create a small php script with one command: passthru("cat /boot/vmlinuz"); 2. Request the script through the web server. The first time it runs it may run quickly and return the proper output, but subsequent times it will randomly take a very long time to return the output, a seeming random amount of time between 10 seconds and 10 minutes. While the script is running, the server will be very unresponsive. Note that /boot/vmlinuz is just an example, any command that returns a significant amount of output, (500K+ such as calling ghostscript to generate a PDF/PS file for the user) will cause the condition. Larger outputs seem to cause the response time to scale up in an exponential growth rate. Actual results: Extreme slowdown of server. Expected results: Almost instant response with data. Additional info: