CVE-2020-5204

Name: CVE-2020-5204
Creator: NVD / NIST
Published: 2020-01-06T20:15:12.523+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 1.08%

Last modified Jun 17, 2026

CVE-2020-5204 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. In uftpd before 2.11, there is a buffer overflow vulnerability in handle_PORT in ftpcmd.c that is caused by a buffer that is 16 bytes large being filled via sprintf() with user input based on the format specifier string %d.%d.%d.%d. The 16 byte size is correct for valid IPv4 addresses (len('255.255.255.255') == 16), but the format specifier %d allows more than 3 digits. EPSS estimates a 1.08% chance of exploitation in the next 30 days.

Description

In uftpd before 2.11, there is a buffer overflow vulnerability in handle_PORT in ftpcmd.c that is caused by a buffer that is 16 bytes large being filled via sprintf() with user input based on the format specifier string %d.%d.%d.%d. The 16 byte size is correct for valid IPv4 addresses (len('255.255.255.255') == 16), but the format specifier %d allows more than 3 digits. This has been fixed in version 2.11

Metrics

CVSS 3.1

8.8/10

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

EPSS Probability

1.08%

60.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Troglobit	Uftpd	< 2.11

References

http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00034.html
https://github.com/troglobit/uftpd/commit/0fb2c031ce0ace07cc19cd2cb2143c4b5a63c9ddPatch, Third Party Advisory
https://github.com/troglobit/uftpd/security/advisories/GHSA-wrpr-xw7q-9wvqThird Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00034.html
https://github.com/troglobit/uftpd/commit/0fb2c031ce0ace07cc19cd2cb2143c4b5a63c9ddPatch, Third Party Advisory
https://github.com/troglobit/uftpd/security/advisories/GHSA-wrpr-xw7q-9wvqThird Party Advisory

Timeline

Published: Jan 6, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-5204?

How severe is CVE-2020-5204?

CVE-2020-5204 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 1.08% probability of exploitation in the next 30 days.

How do I fix CVE-2020-5204?

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-2020-5204?

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

Scan your code now

Source: NVD / NIST