{"cve":"CVE-2020-1959","nvd":{"published":"2020-05-04T13:15:13.533","modified":"2026-06-17T03:02:43.627","status":"Modified","description":"A Server-Side Template Injection was identified in Apache Syncope prior to 2.1.6 enabling attackers to inject arbitrary Java EL expressions, leading to an unauthenticated Remote Code Execution (RCE) vulnerability. Apache Syncope uses Java Bean Validation (JSR 380) custom constraint validators. When building custom constraint violation error messages, they support different types of interpolation, including Java EL expressions. Therefore, if an attacker can inject arbitrary data in the error message template being passed, they will be able to run arbitrary Java code.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-917"],"references":["http://syncope.apache.org/security","http://syncope.apache.org/security"],"products":["apache:syncope"],"source":"nvd","synced_at":"2026-10-19T21:04:18.695612450+00:00"},"epss":{"cve":"CVE-2020-1959","score":0.04982,"percentile":0.92211,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-vjqw-r3ww-wj2w","url":"https://osv.dev/vulnerability/GHSA-vjqw-r3ww-wj2w","summary":"Expression Language Injection in Apache Syncope","modified":"2023-11-08T04:02:47.307604Z","packages":[{"ecosystem":"Maven","name":"org.apache.syncope:syncope-core","purl":"pkg:maven/org.apache.syncope/syncope-core","ranges":["<2.1.6"],"fixed":["2.1.6"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}