An issue was discovered in the Quiz and Survey Master plugin before 7.0.1 for WordPress. It made it possible for unauthenticated attackers to upload arbitrary files and achieve remote code execution. If a quiz question could be answered by uploading a file, only the Content-Type header was checked during the upload, and thus the attacker could use text/plain for a .php file.

References

• https://nvd.nist.gov/vuln/detail/CVE-2020-35949
• https://wpscan.com/vulnerability/10349
• https://www.wordfence.com/blog/2020/08/critical-vulnerabilities-patched-in-quiz-and-survey-master-plugin/