CVE-2020-20277

Name: CVE-2020-20277
Creator: NVD / NIST
Published: 2020-12-18T19:15:14.11+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 25.25%

Last modified Jun 17, 2026

CVE-2020-20277 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. There are multiple unauthenticated directory traversal vulnerabilities in different FTP commands in uftpd FTP server versions 2.7 to 2.10 due to improper implementation of a chroot jail in common.c's compose_abspath function that can be abused to read or write to arbitrary files on the filesystem, leak process memory, or potentially lead to remote code execution.. EPSS estimates a 25.25% chance of exploitation in the next 30 days.

Description

There are multiple unauthenticated directory traversal vulnerabilities in different FTP commands in uftpd FTP server versions 2.7 to 2.10 due to improper implementation of a chroot jail in common.c's compose_abspath function that can be abused to read or write to arbitrary files on the filesystem, leak process memory, or potentially lead to remote code execution.

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

25.25%

97.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-22

Affected Software

Vendor	Product	Versions
Troglobit	Uftpd	>= 2.7, <= 2.10

References

http://packetstormsecurity.com/files/167908/uftpd-2.10-Directory-Traversal.htmlExploit, Third Party Advisory, VDB Entry
https://arinerron.com/blog/posts/6Third Party Advisory
https://github.com/troglobit/uftpd/commit/455b47d3756aed162d2d0ef7f40b549f3b5b30fePatch, Third Party Advisory
http://packetstormsecurity.com/files/167908/uftpd-2.10-Directory-Traversal.htmlExploit, Third Party Advisory, VDB Entry
https://arinerron.com/blog/posts/6Third Party Advisory
https://github.com/troglobit/uftpd/commit/455b47d3756aed162d2d0ef7f40b549f3b5b30fePatch, Third Party Advisory

Timeline

Published: Dec 18, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-20277?

How severe is CVE-2020-20277?

CVE-2020-20277 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 25.25% probability of exploitation in the next 30 days.

How do I fix CVE-2020-20277?

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-2020-20277?

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

Scan your code now

Source: NVD / NIST