CVE-2021-29416

Name: CVE-2021-29416
Creator: NVD / NIST
Published: 2021-03-29T18:15:13.407+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 1.15%

Last modified Jun 17, 2026

CVE-2021-29416 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. An issue was discovered in PortSwigger Burp Suite before 2021.2. During viewing of a malicious request, it can be manipulated into issuing a request that does not respect its upstream proxy configuration. EPSS estimates a 1.15% chance of exploitation in the next 30 days.

Description

An issue was discovered in PortSwigger Burp Suite before 2021.2. During viewing of a malicious request, it can be manipulated into issuing a request that does not respect its upstream proxy configuration. This could leak NetNTLM hashes on Windows systems that fail to block outbound SMB.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

1.15%

62.8th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Portswigger	Burp Suite	< 2021.2

References

https://hackerone.com/reports/1054382Exploit, Issue Tracking, Third Party Advisory
https://portswigger.net/burp/releases/professional-community-2020-12?requestededition=professionalRelease Notes, Vendor Advisory
https://hackerone.com/reports/1054382Exploit, Issue Tracking, Third Party Advisory
https://portswigger.net/burp/releases/professional-community-2020-12?requestededition=professionalRelease Notes, Vendor Advisory

Timeline

Published: Mar 29, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-29416?

How severe is CVE-2021-29416?

CVE-2021-29416 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 1.15% probability of exploitation in the next 30 days.

How do I fix CVE-2021-29416?

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-2021-29416?

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

Scan your code now

Source: NVD / NIST