Vulnerability in Go-Proxyproto Project

CVE-2021-23351

The package github.com/pires/go-proxyproto before 0.5.0 are vulnerable to Denial of Service (DoS) via the parseVersion1() function. The reader in this package is a default bufio.Reader wrapping a net.Conn. It will read from the connection until it finds a newline. Since no limits are implemented in the code, a deliberately malformed V1 header could be used to exhaust memory in a server process using this code - and create a DoS. This can be exploited by sending a stream starting with PROXY and continuing to send data (which does not contain a newline) until the target stops acknowledging. The risk here is small, because only trusted sources should be allowed to send proxy protocol headers.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.019 (78.6th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 79th percentile — 78.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2021-23351: held from 0.019 to 0.019.

EPSS over last 30 days · oldest: 0.019 · newest: 0.019 · change: 0.000

Affected products

References

Frequently asked questions

What is CVE-2021-23351?
CVE-2021-23351 is a medium-severity vulnerability in Go-Proxyproto Project. CVSS score: 4.4/10. Published 2021-03-08.
How severe is CVE-2021-23351?
Medium severity. CVSS v3 base score is 4.4 out of 10.