XSS in Mock-Server Mockserver
CVE-2021-32827
MockServer is open source software which enables easy mocking of any system you integrate with via HTTP or HTTPS. An attacker that can trick a victim into visiting a malicious site while running MockServer locally, will be able to run arbitrary code on the MockServer machine. With an overly broad default CORS configuration MockServer allows any site to send cross-site requests. Additionally, MockServer allows you to create dynamic expectations using Javascript or Velocity templates. Both engines may allow an attacker to execute arbitrary code on-behalf of MockServer. By combining these two issues (Overly broad CORS configuration + Script injection), an attacker could serve a malicious page so that if a developer running MockServer visits it, they will get compromised. For more details including a PoC see the referenced GHSL-2021-059.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.022 (81.5th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 82nd percentile — 81.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.022 · newest: 0.022 · change: 0.000
Affected products
- Mock-Server Mockserver — versions all
- Oracle Communications Cloud Native Core Policy — versions 1.14.0
Weakness classification (CWE)
References
- securitylab.github.com/advisories/GHSL-2021-059-mockserver/ (Exploit, Third Party Advisory)
- www.oracle.com/security-alerts/cpujan2022.html (Patch, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-32827?
- CVE-2021-32827 is a medium-severity vulnerability in Mock-Server Mockserver, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 6.1/10. Published 2021-08-16.
- How severe is CVE-2021-32827?
- Medium severity. CVSS v3 base score is 6.1 out of 10.