CVE-2021-23351Medium· 4.9▾ Sunlitgithub.com/pires/go-proxyproto denial of service vulnerability
▾ Sunlit zone — Low / medium · no exploitation signal
impact 27 · likelihood 0.4 · exploitation 0
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Exploit-prediction probability, daily snapshots since Jul 9.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via OSV
Last analysed / modified upstream
1.9%
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.
github.com/pires/go-proxyproto < 0.5.0Upgrade to a patched release:
github.com/pires/go-proxyproto 0.5.0