{"id":"GHSA-cqh3-jg8p-336j","summary":"Yamcs Vulnerable to LDAP Injection in LdapAuthModule","details":"### Summary\n\nAn LDAP injection vulnerability exists in `org.yamcs.security.LdapAuthModule` when constructing search filters. The username parameter is inserted directly into the LDAP filter without proper RFC 4515 escaping.\n\n### Root Cause\n\n**File:** `yamcs-core/src/main/java/org/yamcs/security/LdapAuthModule.java:233`\n\nThe `username` parameter is inserted directly into an LDAP search filter without RFC 4515 escaping:\n\n```java\n// VULNERABLE\nvar filter = userFilter.replace(\"{0}\", username);\nvar searchResult = getSingleResult(ctx, userBase, filter, controls);\n```\n\nLDAP wildcard characters (`*`, `(`, `)`) are accepted without sanitization.\n\n### Impact\n\nWith a known valid password, `username=*` authenticates as the first user returned by the LDAP search — enabling horizontal privilege escalation between accounts sharing similar passwords or when the attacker knows one valid password.\n\nThis affects deployments that use `org.yamcs.security.LdapAuthModule` in their `etc/security.yaml` configuration file.\n\n### Proof of Concept\n\n```bash\ncurl -X POST \"http://TARGET:8090/auth/token\" \\\n  -d \"grant_type=password&username=*&password=known_password\"\n# Returns token for first matching LDAP user\n```\n\n### Fix\n\nApply RFC 4515 escaping before filter construction:\n\n```java\nprivate static String escapeLdapFilter(String input) {\n    return input\n        .replace(\"\\\\\", \"\\\\5c\")\n        .replace(\"*\",  \"\\\\2a\")\n        .replace(\"(\",  \"\\\\28\")\n        .replace(\")\",  \"\\\\29\")\n        .replace(\"\\0\", \"\\\\00\");\n}\nvar filter = userFilter.replace(\"{0}\", escapeLdapFilter(username));\n```","aliases":["CVE-2026-42568"],"modified":"2026-06-11T14:15:10.478690253Z","published":"2026-05-26T23:39:55Z","database_specific":{"github_reviewed_at":"2026-05-26T23:39:55Z","nvd_published_at":"2026-06-10T23:16:46Z","cwe_ids":["CWE-90"],"severity":"MODERATE","github_reviewed":true},"references":[{"type":"WEB","url":"https://github.com/yamcs/yamcs/security/advisories/GHSA-cqh3-jg8p-336j"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42568"},{"type":"PACKAGE","url":"https://github.com/yamcs/yamcs"},{"type":"WEB","url":"https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.7"},{"type":"WEB","url":"https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.0"}],"affected":[{"package":{"name":"org.yamcs:yamcs-core","ecosystem":"Maven","purl":"pkg:maven/org.yamcs/yamcs-core"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.12.7"}]}],"versions":["0.29.3","0.30.0","3.0.0","3.1.0","3.1.1","3.1.2","3.2.0","3.2.1","3.2.2","3.3.0","3.3.1","3.4.0","3.4.1","3.4.11","3.4.2","3.4.3","3.4.4","3.4.5","3.4.6","3.4.8","4.0.0","4.0.1","4.1.1","4.1.2","4.10.0","4.10.1","4.10.2","4.10.3","4.10.4","4.10.5","4.10.6","4.10.7","4.10.8","4.10.9","4.2.0","4.2.1","4.2.2","4.3.0","4.3.1","4.4.0","4.4.1","4.4.2","4.5.0","4.6.0","4.6.1","4.6.2","4.6.3","4.7","4.7.1","4.7.3","4.8.0","4.8.1","4.9.0","4.9.1","4.9.2","4.9.3","4.9.4","5.0.0","5.1.0","5.1.1","5.1.2","5.1.3","5.1.4","5.10.0","5.10.1","5.10.10","5.10.11","5.10.12","5.10.2","5.10.3","5.10.4","5.10.5","5.10.6","5.10.7","5.10.8","5.10.9","5.11.0","5.11.1","5.11.10","5.11.11","5.11.12","5.11.13","5.11.2","5.11.3","5.11.4","5.11.5","5.11.6","5.11.7","5.11.8","5.11.9","5.12.0","5.12.1","5.12.2","5.12.3","5.12.4","5.12.5","5.12.6","5.2.0","5.2.1","5.2.2","5.2.3","5.2.4","5.2.5","5.2.6","5.3.0","5.3.1","5.3.2","5.3.3","5.3.4","5.3.5","5.3.6","5.4.0","5.4.1","5.4.2","5.4.3","5.4.4","5.4.5","5.5.0","5.5.1","5.5.2","5.5.3","5.5.4","5.5.5","5.5.6","5.5.7","5.6.0","5.6.1","5.6.2","5.7.0","5.7.1","5.7.10","5.7.11","5.7.12","5.7.13","5.7.2","5.7.3","5.7.4","5.7.5","5.7.6","5.7.7","5.7.8","5.7.9","5.8.0","5.8.1","5.8.2","5.8.3","5.8.4","5.8.5","5.8.6","5.8.7","5.8.8","5.9.0","5.9.1","5.9.10","5.9.11","5.9.12","5.9.2","5.9.3","5.9.4","5.9.5","5.9.6","5.9.7","5.9.8","5.9.8.1","5.9.9"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-cqh3-jg8p-336j/GHSA-cqh3-jg8p-336j.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"}]}