CVE-2021-47667

An OS command injection vulnerability in lib/NSSDropoff.php in ZendTo 5.24-3 through 6.x before 6.10-7 allows unauthenticated remote attackers to execute arbitrary commands via shell metacharacters in the tmp_name parameter when dropping off a file via a POST /dropoff request.

Published: 2025-04-05 Last update: 2026-04-15 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-47667 is rated High Risk (73.2/100): CVSS Critical severity, with high exploitation likelihood (EPSS 8.87%, 93th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-47667

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-15 8.09% 8.87% +0.78%
2 2026-05-14 1.10% 8.09% +6.99%
3 2026-01-30 1.10%

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-47667

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
10.0 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 6.0 [email protected]

Weakness enumeration for CVE-2021-47667

Affected software / configurations for CVE-2021-47667

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2021-47667

cvelogic Threat Intelligence