PostgreSQL optimizer statistics allow a user to read sampled data within a view that the user cannot access. Separately, statistics allow a user to read sampled data that a row security policy intended to hide. PostgreSQL maintains statistics for tables by sampling data available in columns; this data is consulted during the query planning process. Prior to this release, a user could craft a leaky operator that bypassed view access control lists (ACLs) and bypassed row security policies in partitioning or table inheritance hierarchies. Reachable statistics data notably included histograms and most-common-values lists. CVE-2017-7484 and CVE-2019-10130 intended to close this class of vulnerability, but this gap remained. Versions before PostgreSQL 17.6, 16.10, 15.14, 14.19, and 13.22 are affected.
The product prevents direct access to a resource containing sensitive information, but it does not sufficiently limit access to metadata that is derived from the original, sensitive information.
Developers might correctly prevent unauthorized access to a database or other resource containing sensitive information, but they might not consider that portions of the original information might also be recorded in metadata, search indices, statistical reports, or other resources. If these resources are not also restricted, then attackers might be able to extract some or all of the original information, or otherwise infer some details. For example, an attacker could specify search terms that are known to be unique to a particular person, or view metadata such as activity or creation dates in order to identify usage patterns.