CVE-2021-27850 Scanner.
Apache Tapestry - Remote Code Execution
Free and read-only. Scan only sites you own or are allowed to test.
What This Check Does.
Read-only
It only asks your site for public pages, the way a browser would. Nothing is changed, uploaded or stored.
Up to 2 requests
A small, fixed number of requests, so the check is quick and will not load your site.
Looks for CVE-2021-27850
It looks for the specific sign of this one vulnerability and ends with a clear answer: vulnerable, not vulnerable, or could not be determined.
About CVE-2021-27850. What It Means.
Apache Tapestry contains a critical unauthenticated remote code execution vulnerability. Affected versions include 5.4.5, 5.5.0, 5.6.2 and 5.7.0. Note that this vulnerability is a bypass of the fix for CVE-2019-0195. Before that fix it was possible to download arbitrary class files from the classpath by providing a crafted asset file URL.
FAQ
Common Questions.
Apache Tapestry - Remote Code Execution. Apache Tapestry contains a critical unauthenticated remote code execution vulnerability. Affected versions include 5.4.5, 5.5.0, 5.6.2 and 5.7.0. Note that this vulnerability is a bypass of the fix for CVE-2019-0195. Before that fix it was possible to download arbitrary class files from the classpath by providing a crafted asset file URL.
Atlas sends up to 2 read-only requests to your site and looks for the specific sign of CVE-2021-27850 in Apache Tapestry. Nothing is changed, uploaded or stored on your site.
CVE-2021-27850 is not on the CISA Known Exploited Vulnerabilities list at the time of writing, but it is still worth fixing. Its CVSS score is 9.8.
Yes. The check only reads public pages, the same way a browser or a search engine would. Scan only sites you own or are allowed to test.
It means no sign of CVE-2021-27850 was found by this read-only check. It does not prove the site is free of other weaknesses.
Update Apache Tapestry to the latest version from the vendor, or follow the vendor's advice to switch off the affected feature. The vendor links and details are in the CVE-2021-27850 briefing linked on this page.
Scan only sites you own or have written permission to test. A result of Not Vulnerable means this read-only check found no sign of CVE-2021-27850; it is not a guarantee that the site is secure.