The theme editor in Bolt before 2.2.5 does not check the file extension when renaming files, which allows remote authenticated users to execute arbitrary code by renaming a crafted file and then directly accessing it.

References

• https://nvd.nist.gov/vuln/detail/CVE-2015-7309
• https://bolt.cm/newsitem/bolt-2-2-5-released
• https://www.exploit-db.com/exploits/38196/
• http://blog.curesec.com/article/blog/Bolt-224-Code-Execution-44.html
• http://packetstormsecurity.com/files/133539/CMS-Bolt-2.2.4-File-Upload.html
• http://seclists.org/fulldisclosure/2015/Aug/66
• http://www.rapid7.com/db/modules/exploit/multi/http/bolt_file_upload