Authentication bypass via second StartupMessage during SCRAM authentication in PgBouncer

Improper authentication in PgBouncer 1.17.0 through 1.26.0 allows a remote attacker who knows the password of a user listed in auth_file to log in as any other user that authenticates using SCRAM, including PgBouncer admin users and backend superusers. A second StartupMessage sent during SCRAM authentication against a non-existent database is not rejected and switches the user being logged in as, while the SCRAM exchange is still verified against the keys of the first user.

Integer overflow causes an infinite loop in message buffer growth in PgBouncer

Integer overflow in the message buffer growth logic (mbuf_make_room) in PgBouncer 1.21.0 through 1.26.0 allows a remote attacker to cause a denial of service when max_packet_size is configured above 2147483648. A packet header declaring a length above 2^31 makes the buffer size computation overflow, leaving the growth loop unable to terminate. Because PgBouncer serves all clients from a single process, this saturates a CPU core and stalls every pooled connection until the process is restarted. Since 1.23.0 the overflow is reachable before authentication with a five-byte packet header.

Infinite loop on empty option name in startup options parameter in PgBouncer

An infinite loop in PgBouncer 1.20.0 through 1.26.0 allows an unauthenticated remote attacker to cause a denial of service. A StartupMessage whose options parameter contains an empty parameter name, such as "-c=", makes the ignore_startup_parameters list lookup loop forever. Because PgBouncer serves all clients from a single process, this saturates a CPU core and makes PgBouncer unresponsive to all clients until the process is restarted.

Unbounded SCRAM iteration count causes CPU exhaustion in PgBouncer

Missing upper bound on the key derivation iteration count accepted during SCRAM authentication to a backend server in PgBouncer through 1.25.2 allows a malicious or compromised PostgreSQL backend to cause uncontrolled CPU consumption in PgBouncer. The resulting key derivation cannot be interrupted in frontend builds such as PgBouncer. Because PgBouncer serves all clients from a single process, one backend can in this way stop it from serving traffic for every other database and client it is pooling, so the failure of a single backend is not contained.

NULL pointer dereference in SCRAM client-final-message parsing in PgBouncer

Missing validation of a mandatory attribute in the SCRAM client-final-message parser in PgBouncer through 1.25.2 allows an unauthenticated remote attacker to crash the process. A malformed message can make the parser report success while leaving a required value unset, which is then dereferenced as a NULL pointer. The crash occurs before any credential is verified, so no valid account is required. Because PgBouncer serves all clients from a single process, this terminates every pooled connection.

Integer overflow causes an infinite loop in packet buffer growth in PgBouncer

Integer overflow in the packet buffer growth logic in PgBouncer through 1.25.2 allows an unauthenticated remote attacker to cause a denial of service. Sufficiently large input makes the buffer size computation overflow, leaving the growth loop unable to terminate. Because PgBouncer serves all clients from a single process, this saturates a CPU core and stalls every pooled connection until the process is killed. Both unauthenticated and authenticated code paths can reach the overflow.

PgBouncer crash in kill_pool_logins_server_error

A possible null pointer reference in PgBouncer before 1.25.2 could lead to a crash, if a server sends an error response without SQLSTATE field.

PgBouncer integer overflow in PgBouncer network packet parsing

An integer overflow in network packet parsing code in PgBouncer before 1.25.2 bypasses a boundary check and can lead to a crash. An unauthenticated remote attacker can crash PgBouncer with a malformed SCRAM authentication packet.

PgBouncer buffer overflow in SCRAM

The SCRAM code in PgBouncer before 1.25.2 did not check the return value of strlcat() correctly when building the contents of the SCRAM client-final-message. A malicious backend that sends a SCRAM server-final-message with a long nonce can trigger a stack overflow.

PgBouncer missing authorization check in KILL_CLIENT admin command

PgBouncer before 1.25.2 did not perform an appropriate authorization check for the KILL_CLIENT admin command. All users with access to the administration console (which itself requires authorization) could run this command. It would have been correct to allow only users listed in the admin_users parameter.

Untrusted search path in auth_query connection in PgBouncer

Untrusted search path in auth_query connection handler in PgBouncer before 1.25.1 allows an unauthenticated attacker to execute arbitrary SQL during authentication via a malicious search_path parameter in the StartupMessage.

PgBouncer default auth_query does not take Postgres password expiry into account

Password can be used past expiry in PgBouncer due to auth_query not taking into account Postgres its VALID UNTIL value, which allows an attacker to log in with an already expired password

When PgBouncer is configured to use "cert" authentication, a man-in-the-middle attacker can inject arbitrary SQL queries when a connection is first established, despite the use of TLS certificate verification and encryption. This flaw affects PgBouncer versions prior to 1.16.1.

PgBouncer before 1.5.5 allows remote attackers to cause a denial of service (NULL pointer dereference and crash) by sending a password packet before a startup packet.

PgBouncer 1.6.x before 1.6.1, when configured with auth_user, allows remote attackers to gain login access as auth_user via an unknown username.

c-ares: Missing input validation of host names may lead to domain hijacking

A flaw was found in c-ares library, where a missing input validation check of host names returned by DNS (Domain Name Servers) can lead to output of wrong hostnames which might potentially lead to Domain Hijacking. The highest threat from this vulnerability is to confidentiality and integrity as well as system availability.