{"id":"UBUNTU-CVE-2021-23351","details":"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.","modified":"2025-09-08T16:46:59Z","published":"2021-03-08T05:15:00Z","upstream":["CVE-2021-23351"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-23351"},{"type":"REPORT","url":"https://github.com/pires/go-proxyproto/commit/7f48261db810703d173f27f3309a808cc2b49b8b"},{"type":"REPORT","url":"https://github.com/pires/go-proxyproto/issues/69"},{"type":"REPORT","url":"https://github.com/pires/go-proxyproto/pull/71"},{"type":"REPORT","url":"https://snyk.io/vuln/SNYK-GOLANG-GITHUBCOMPIRESGOPROXYPROTO-1081577"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-23351"}],"affected":[{"package":{"name":"golang-github-pires-go-proxyproto","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/golang-github-pires-go-proxyproto@0.4.2-1?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.4.2-1"],"ecosystem_specific":{"binaries":[{"binary_name":"golang-github-pires-go-proxyproto-dev","binary_version":"0.4.2-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-23351.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}