Dgraph: Pre-Auth Full Database Exfiltration via DQL Injection in Upsert Condition Field

Dgraph is an open source distributed GraphQL database. Prior to 25.3.3, a vulnerability has been found in Dgraph that gives an unauthenticated attacker full read access to every piece of data in the database. This affects Dgraph's default configuration where ACL is not enabled. The attack is a single HTTP POST to /mutate?commitNow=true containing a crafted cond field in an upsert mutation. The cond value is concatenated directly into a DQL query string via strings.Builder.WriteString after only a cosmetic strings.Replace transformation. No escaping, parameterization, or structural validation is applied. An attacker injects an additional DQL query block into the cond string, which the DQL parser accepts as a syntactically valid named query block. The injected query executes server-side and its results are returned in the HTTP response. This vulnerability is fixed in 25.3.3.