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CVE-2020-1959
CRITICAL
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.
Published: May 4, 2020
Modified: Jun 17, 2026
CWE-917
CVSS Metrics
CVSSv3
Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected Products (1)
| Vendor | Product | Version |
|---|---|---|
| apache | syncope | * ≥ 2.1.0 < 2.1.6 |
GitHub Security Advisory GHSA-vjqw-r3ww-wj2w
Expression Language Injection in Apache Syncope
maven
org.apache.syncope:syncope-core
< 2.1.6
Fixed: 2.1.6
References (2)
- http://syncope.apache.org/security Vendor Advisory
- http://syncope.apache.org/security Vendor Advisory
Risk Scores
CVSS Score
9.8 / 10
EPSS Score
4.82%
Top 9% most likely to be exploited
Threat Score
40.6 / 100
Data Sources
NVD
EPSS
GitHub