The fix issued for CVE-2020-17530 was incomplete. So from Apache Struts 2.0.0 to 2.5.29, still some of the tag’s attributes could perform a double evaluation if a developer applied forced OGNL evaluation by using the %{…} syntax. Using forced OGNL evaluation on untrusted user input can lead to a Remote Code Execution and security degradation.
[
{
"product": "Apache Struts",
"vendor": "Apache Software Foundation",
"versions": [
{
"status": "affected",
"version": "2.0.0 to 2.5.29"
}
]
}
]