NVD / CVE Program· CNA mitre

CVE-2020-35951: An issue was discovered in the Quiz and Survey Master plugin before 7.0.1 for WordPress.

Noroxi assessment

Priority: This week (action score 62/100)

A ready-made attack module is public (Nuclei); exploiting it takes no special expertise.
Public proof-of-concept code exists (Exploit-DB / GitHub); there is no record of exploitation in the wild.
Probability of exploitation in the next 30 days: 76.3% (FIRST EPSS); higher than 99.5% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to the record, no fixed version is available yet.

Don’t wait for the next maintenance window. Until a fix is released, restrict access to the affected component and follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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).

CriticalCVSS 9.9 · v3.1—Proof of concept No fix recorded

Published: Jan 1, 2021
Updated: Jun 16, 2026
EPSS: 76.3% · 99th percentile
CWE: CWE-306

Report tools

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Action score

This week

Don’t wait for the next maintenance window.

CVSS: 39 / 40 · 9.9 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 23 / 30 · 76.3%

CNA vs NVD score

NVD: 9.9
CNA · mitre: 9.9; agree

CVSS:3.1/AC:L/AV:N/A:H/C:L/I:L/PR:N/S:C/UI:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
Proof of concept exists, no weaponized module
No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
expresstech	quiz and survey master	cpe:2.3:a:expresstech:quiz_and_survey_master

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

expresstech quiz and survey masterbefore 7.0.1

Same product

expresstech: all records

Other highest-scoring records for the same primary product.

CVE-2020-35949An issue was discovered in the Quiz and Survey Master plugin before 7.0.1 for WordPress.
41Plan
CVE-2022-41652WordPress Quiz And Survey Master plugin <= 7.3.10 - Bypass vulnerability
39Monitor
CVE-2023-28787WordPress Quiz And Survey Master plugin <= 8.1.4 - Unauthenticated SQL Injection vulnerability
38Monitor

Published before and after this one in the same product

← EarlierCVE-2019-17599Dec 13, 2019 · The quiz-master-next (aka Quiz And Survey Master) plugin before 6.3.5 for WordPress is affected by: Cross Site Scripting (XSS).
24Monitor
← EarlierCVE-2016-11085Aug 16, 2020 · php/qmn_options_questions_tab.php in the quiz-master-next plugin before 4.7.9 for WordPress allows CSRF, with resultant stored XSS, via the
26Monitor
Later →CVE-2021-24221Apr 12, 2021 · Quiz And Survey Master < 7.1.12 - Authenticated SQL injection via shortcode
36Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

Nuclei detection template ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
Source	Kind	Date
Nuclei detection template	Nuclei template CVE-2020-35951	—

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

—

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

CVE-2021-24221101 days apartQuiz And Survey Master < 7.1.12 - Authenticated SQL injection via shortcode
36Monitor

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: low · data can be read
Integrity: low · data or configuration can be modified
Availability: high · the service can be disrupted

Impact can extend beyond the vulnerable component (scope changes).

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Changed
Confidentiality impact: Low
Integrity impact: Low
Availability impact: High

Weakness class (CWE)

CWE-306 · Missing Authentication for Critical Function

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:H

nvd-primary

Root cause

A function added for development or support ships to production without authentication. It often relies on the assumption that it is “only reachable from the internal network.”

The bug in code

The whole CWE-306 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1// Added for the support team
2app.post("/maintenance/reset", resetDevice);

Fixed

1if (config.maintenanceEnabled) {
2  app.post(
3    "/maintenance/reset",
4    requireSession, requireRole("admin"), resetDevice
5  );
6}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

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Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

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