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CVE-2021-32827

CRITICALCVSS 9.6/10EPSS 2.16%

Last modified

CVE-2021-32827 is a critical-severity vulnerability rated 9.6/10 on the CVSS scale. 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. EPSS estimates a 2.16% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1
9.6/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

EPSS Probability
2.16%

79.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
Mock-ServerMockserverAll versions
OracleCommunications Cloud Native Core Policy1.14.0

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is 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.
How severe is CVE-2021-32827?
CVE-2021-32827 has a CVSS score of 9.6/10 (CRITICAL severity). The EPSS model estimates a 2.16% probability of exploitation in the next 30 days.
How do I fix CVE-2021-32827?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-32827?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST