RCE in Apache Syncope

CVE-2020-1959

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.

Vulnerability class: Log4Shell (CVE-2021-44228)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.050 (92.2th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 92nd percentile — 92.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2020-1959: held from 0.050 to 0.050.

EPSS over last 30 days · oldest: 0.050 · newest: 0.050 · change: 0.000

Affected products

  • Apache Syncope
  • Apache Syncope — versions Apache Syncope 2.1.X releases prior to 2.1.6

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2020-1959?
CVE-2020-1959 is a critical-severity vulnerability in Apache Syncope, classified under Improper Neutralization of Special Elements used in an Expression Language Statement (Expression Language Injection). CVSS score: 9.8/10. Published 2020-05-04.
How severe is CVE-2020-1959?
Critical severity. CVSS v3 base score is 9.8 out of 10.