BlackTreeIndependent security intelligencesysown · proxysql
Critical technical impact with a remotely reachable, unauthenticated path and a public exploit reference; no CISA KEV confirmation is currently recorded.
Critical technical impact with a remotely reachable, unauthenticated path and a public exploit reference; no CISA KEV confirmation is currently recorded.
Fix not verifiedProxySQL is a proxy for MySQL and its forks, as well as PostgreSQL. In versions 2.0.0 through 3.0.8, the ProxySQL MySQL frontend accepts the `PROXY UNKNOWN <addr> <addr> <port> <port>\r\n` PP1 frame as a well-formed PROXY protocol header. The HAProxy PROXY protocol v1 specification says that when the protocol token is `UNKNOWN`, the receiver MUST ignore any address fields that follow it, because the proxy has declared it cannot determine the client identity. ProxySQL parses those address fields anyway via `sscanf` and writes the spoofed source address into the session's `addr.addr` field. From there it flows directly into the query-rule matcher, where the `client_addr` predicate decides routing and ACL. When `mysql-proxy_protocol_networks = '*'` (the default), any TCP peer can send a PP1 frame and choose any source IP claim. With that, any `mysql_query_rules` row pinned to a `client_addr` value is forgeable: the attacker writes the address they want to match into the PP1 line, and ProxySQL routes their query as if it came from that address. In practice this is a routing and ACL bypass. Real deployments use `client_addr` for read-write splitting (internal apps go to the primary, public traffic to read replicas), per-app schema pinning, and query-filter rules (DDL allowed only from admin CIDR, public queries blocked from dangerous patterns). An attacker that can reach the frontend port can forge their way into any of those routes. Version 3.0.9 patches this issue.
ProxySQL is a proxy for MySQL and its forks, as well as PostgreSQL. In versions 2.0.0 through 3.0.8, the ProxySQL MySQL frontend accepts the `PROXY UNKNOWN <addr> <addr> <port> <port>\r\n` PP1 frame as a well-formed PROXY protocol header. The HAProxy PROXY protocol v1 specification says that when the protocol token is `UNKNOWN`, the receiver MUST ignore any address fields that follow it, because the proxy has declared it cannot determine the client identity. ProxySQL parses those address fields anyway via `sscanf` and writes the spoofed source address into the session's `addr.addr` field. From there it flows directly into the query-rule matcher, where the `client_addr` predicate decides routing and ACL. When `mysql-proxy_protocol_networks = '*'` (the default), any TCP peer can send a PP1 frame and choose any source IP claim. With that, any `mysql_query_rules` row pinned to a `client_addr` value is forgeable: the attacker writes the address they want to match into the PP1 line, and ProxySQL routes their query as if it came from that address. In practice this is a routing and ACL bypass. Real deployments use `client_addr` for read-write splitting (internal apps go to the primary, public traffic to read replicas), per-app schema pinning, and query-filter rules (DDL allowed only from admin CIDR, public queries blocked from dangerous patterns). An attacker that can reach the frontend port can forge their way into any of those routes. Version 3.0.9 patches this issue.
The product has two different sources of the same data or information, but it uses the source that has less support for verification, is less trusted, or is less resistant to attack.
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
ProxySQL is a proxy for MySQL and its forks, as well as PostgreSQL. In versions 2.0.0 through 3.0.8, the ProxySQL MySQL frontend accepts the `PROXY UNKNOWN <addr> <addr> <port> <port>\r\n` PP1 frame as a well-formed PROXY protocol header. The HAProxy PROXY protocol v1 specification says that when the protocol token is `UNKNOWN`, the receiver MUST ignore any address fields that follow it, because the proxy has declared it cannot determine the client identity. ProxySQL parses those address fields anyway via `sscanf` and writes the spoofed source address into the session's `addr.addr` field. From there it flows directly into the query-rule matcher, where the `client_addr` predicate decides routing and ACL. When `mysql-proxy_protocol_networks = '*'` (the default), any TCP peer can send a PP1 frame and choose any source IP claim. With that, any `mysql_query_rules` row pinned to a `client_addr` value is forgeable: the attacker writes the address they want to match into the PP1 line, and ProxySQL routes their query as if it came from that address. In practice this is a routing and ACL bypass. Real deployments use `client_addr` for read-write splitting (internal apps go to the primary, public traffic to read replicas), per-app schema pinning, and query-filter rules (DDL allowed only from admin CIDR, public queries blocked from dangerous patterns). An attacker that can reach the frontend port can forge their way into any of those routes. Version 3.0.9 patches this issue.
The product has two different sources of the same data or information, but it uses the source that has less support for verification, is less trusted, or is less resistant to attack.
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.
CWE-348: Use of Less Trusted Source. The product has two different sources of the same data or information, but it uses the source that has less support for verification, is less trusted, or is less resistant to attack.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:NCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
Operational remediation based on structured source evidence.
Published 19 Jun 2026 · Last source change 22 Jun 2026, 15:16 UTC · CWE-348 · Use of Less Trusted Source
Core structured fields are present and their contributing authorities are shown above.
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.