CVE-2021-42071

Exp

In Visual Tools DVR VX16 4.2.28.0, an unauthenticated attacker can achieve remote command execution via shell metacharacters in the cgi-bin/slogin/login.py User-Agent HTTP header.

Published: 2021-10-07 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-42071 is rated High Exploit Risk (89/100): CVSS Critical severity, with high exploitation likelihood (EPSS 91.34%, 100th percentile). 3 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2021-42071

EDB-ID Source Kind Published Link
50098 exploit_db edb 2021-07-06 Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-42071

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 2025-11-21 91.37% 91.34% -0.03%
2 2025-11-18 91.34% 91.37% +0.03%
3 2025-08-06 — 91.34% —

Full EPSS history (43 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-42071

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
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 5.9 [email protected]
10.0 2.0 HIGH
AV:N/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 10.0 10.0 [email protected]

Weakness enumeration for CVE-2021-42071

Affected software / configurations for CVE-2021-42071

Vendor Product Version Raw CPE
visual-tools dvr_vx16_firmware 4.2.28.0 cpe:2.3:o:visual-tools:dvr_vx16_firmware:4.2.28.0:*:*:*:*:*:*:*

References for CVE-2021-42071

URL Tags
https://visual-tools.com/ Vendor Advisory
https://www.exploit-db.com/exploits/50098 Exploit Third Party Advisory VDB Entry
https://www.swascan.com/security-advisory-visual-tools-dvr-cve-2021-42071/ Exploit Third Party Advisory
cvelogic Threat Intelligence