# CVE-2020-35951: CVE-2020-35951

- Exploited (CISA KEV): no
- Published: 2021-01-01
- CVSS: 9.9 CRITICAL (v3.1)
- EPSS: 76.3% (100th percentile)

An issue was discovered in the Quiz and Survey Master plugin before 7.0.1 for WordPress. It allows users to delete arbitrary files such as wp-config.php file, which could effectively take a site offline and allow an attacker to reinstall with a WordPress instance under their control. This occurred via qsm_remove_file_fd_question, which allowed unauthenticated deletions (even though it was only intended for a person to delete their own quiz-answer files).

## Edge WAF coverage (claimed by vendors, not measured)

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | Before feed history | — | — |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | Before feed history | — | — |
| Fastly | Before feed history | — | — |
| F5 | Rule published | 2024-03-12 | 1166 |
| Akamai | No public source | — | — |
| OWASP CRS | Before feed history | — | — |

### F5

- 2024-03-12 · new · rule 200014035
  > Added: signature 200014035 "WordPress Quiz And Survey Master Arbitrary File Deletion" (Abuse of Functionality, risk High), systems: PHP, WordPress. References: CVE-2020-35951.
  Source: https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog

## Our test (measured)

- OWASP Core Rule Set 4.25.0, paranoia level 1, anomaly threshold 5, default CRS settings: passed (0 of 4 requests blocked), template CVE-2020-35951, 2026-11-02
- OWASP Core Rule Set 4.25.0, paranoia level 2, anomaly threshold 5, default CRS settings: passed (0 of 4 requests blocked), template CVE-2020-35951, 2026-11-02

"No public claim" means no vendor statement names this CVE; "Before feed history" means the CVE is older than the vendor feed. In both cases generic rules may still block it.

HTML: https://cve.vigilbase.com/cve/CVE-2020-35951 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2020-35951