AWS Advanced JDBC Wrapper EUVD-2026-34900

Attacker must hold valid low-privilege credentials on the target Amazon Aurora PostgreSQL cluster and possess CREATE permission on a schema that appears earlier in the target user's search_path than the schema of the legitimate function (typically the default public schema). The victim - a higher-privileged user such as rds_superuser - must subsequently connect to the cluster through an application using the affected AWS Advanced JDBC Wrapper (versions prior to 4.0.1) with the GlobalDatabasePlugin enabled, which triggers the unqualified topology detection function call. Exploitation is limited to deployments using the GlobalDatabasePlugin against Aurora PostgreSQL, requires the attacker to wait for a privileged session rather than force one (CVSS UI:P), and is blocked entirely on clusters where CREATE on public has been revoked from low-privileged roles.

The CVSS 4.0 base score of 8.6 (AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H) reflects a network-reachable, low-complexity attack that requires only low-privilege authentication but does depend on passive user interaction (UI:P) - namely, a higher-privileged RDS user subsequently connecting through the affected wrapper, which the attacker cannot directly force. There is no EPSS score, no KEV listing, and no public exploit identified at time of analysis, so this is not a mass-exploitation candidate; however, in shared multi-tenant Aurora PostgreSQL environments where any database user can create objects in public and where rds_superuser sessions routinely use the wrapper, the real risk is high because the attacker patiently waits rather than racing. The SSVC profile (no automatable mass exploitation, but high technical impact via full DB takeover) supports a 'patch promptly' rather than 'emergency' decision. Note that the CVSS vector includes UI:P but the description does not require any active user action - a routine connection by a privileged user is enough - so defenders should not over-discount the UI factor.

A low-privileged tenant on a shared Aurora PostgreSQL cluster creates a malicious function in the public schema whose unqualified name matches a function the GlobalDatabasePlugin invokes during topology detection. When a DBA or automation account with rds_superuser later connects to the cluster through an unpatched AWS Advanced JDBC Wrapper, the wrapper's unqualified query resolves to the attacker's function and executes it under the superuser's session, granting the attacker full database control. No public exploit identified at time of analysis, but the technique is a well-known PostgreSQL search_path hijack pattern.