CVE-2021-42342

Name: CVE-2021-42342
Creator: NVD / NIST
Published: 2021-10-14T06:15:07.037+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 59.46%

Last modified Jun 17, 2026

CVE-2021-42342 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. An issue was discovered in GoAhead 4.x and 5.x before 5.1.5. In the file upload filter, user form variables can be passed to CGI scripts without being prefixed with the CGI prefix. EPSS estimates a 59.46% chance of exploitation in the next 30 days.

Description

An issue was discovered in GoAhead 4.x and 5.x before 5.1.5. In the file upload filter, user form variables can be passed to CGI scripts without being prefixed with the CGI prefix. This permits tunneling untrusted environment variables into vulnerable CGI scripts.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

59.46%

99.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-434

Affected Software

Vendor	Product	Versions
Embedthis	Goahead	>= 4.0.0, <= 4.1.3
Embedthis	Goahead	>= 5.0.0, < 5.1.5

References

https://github.com/embedthis/goahead/issues/305Third Party Advisory
https://github.com/embedthis/goahead/issues/305Third Party Advisory

Timeline

Published: Oct 14, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-42342?

How severe is CVE-2021-42342?

CVE-2021-42342 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 59.46% probability of exploitation in the next 30 days.

How do I fix CVE-2021-42342?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-42342?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST