A flaw was found in PostgreSQL involving the pg_cancel_backend role that signals background workers, including the logical replication launcher, autovacuum workers, and the autovacuum launcher. Successful exploitation requires a non-core extension with a less-resilient background worker and would affect that specific background worker only. This issue may allow a remote high privileged user to launch a denial of service (DoS) attack.

A flaw was found in PostgreSQL that allows authenticated database users to execute arbitrary code through missing overflow checks during SQL array value modification. This issue exists due to an integer overflow during array modification where a remote user can trigger the overflow by providing specially crafted data. This enables the execution of arbitrary code on the target system, allowing users to write arbitrary bytes to memory and extensively read the server's memory.

A memory disclosure vulnerability was found in PostgreSQL that allows remote users to access sensitive information by exploiting certain aggregate function calls with 'unknown'-type arguments. Handling 'unknown'-type values from string literals without type designation can disclose bytes, potentially revealing notable and confidential information. This issue exists due to excessive data output in aggregate function calls, enabling remote users to read some portion of system memory.

It was found that some PostgreSQL extensions did not use search_path safely in their installation script. An attacker with sufficient privileges could use this flaw to trick an administrator into executing a specially crafted script, during the installation or update of such extension. This affects PostgreSQL versions before 12.4, before 11.9, before 10.14, before 9.6.19, and before 9.5.23.

The pg_ctlcluster script in postgresql-common in versions prior to 210 didn't drop privileges when creating socket/statistics temporary directories, which could result in local privilege escalation.

It was discovered that PostgreSQL versions before 10.5, 9.6.10, 9.5.14, 9.4.19, and 9.3.24 failed to properly check authorization on certain statements involved with "INSERT ... ON CONFLICT DO UPDATE". An attacker with "CREATE TABLE" privileges could exploit this to read arbitrary bytes server memory. If the attacker also had certain "INSERT" and limited "UPDATE" privileges to a particular table, they could exploit this to update other columns in the same table.

A vulnerability was found in libpq, the default PostgreSQL client library where libpq failed to properly reset its internal state between connections. If an affected version of libpq was used with "host" or "hostaddr" connection parameters from untrusted input, attackers could bypass client-side connection security features, obtain access to higher privileged connections or potentially cause other impact through SQL injection, by causing the PQescape() functions to malfunction. Postgresql versions before 10.5, 9.6.10, 9.5.14, 9.4.19, and 9.3.24 are affected.

A flaw was found in the way Postgresql allowed a user to modify the behavior of a query for other users. An attacker with a user account could use this flaw to execute code with the permissions of superuser in the database. Versions 9.3 through 10 are affected.

In postgresql 9.3.x before 9.3.21, 9.4.x before 9.4.16, 9.5.x before 9.5.11, 9.6.x before 9.6.7 and 10.x before 10.2, pg_upgrade creates file in current working directory containing the output of `pg_dumpall -g` under umask which was in effect when the user invoked pg_upgrade, and not under 0077 which is normally used for other temporary files. This can allow an authenticated attacker to read or modify the one file, which may contain encrypted or unencrypted database passwords. The attack is infeasible if a directory mode blocks the attacker searching the current working directory or if the prevailing umask blocks the attacker opening the file.