CVE-2020-5206: Opencast kernel Authentication Bypass Vulnerability
CRITICALCVE-2020-5206 is a CRITICAL (CVSS 8.7) authentication bypass vulnerability (CWE-285: Improper Authorization) affecting Opencast kernel libraries in the Maven ecosystem. The issue involves authentication bypass for endpoints with anonymous access in opencast. Remediation is available by upgrading affected packages to version 7.6, 8.1.
CVE-2020-5206 at a Glance
Security Impact
CVSS: 8.7
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N).
How to Fix CVE-2020-5206
To remediate this vulnerability, upgrade all affected Opencast kernel dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
<dependency>
<groupId>org.opencastproject</groupId>
<artifactId>opencast-kernel</artifactId>
<version>7.6</version>
</dependency><dependency>
<groupId>org.opencastproject</groupId>
<artifactId>opencast-kernel</artifactId>
<version>8.1</version>
</dependency>Run the following command in your project directory to verify that all resolved dependencies use the patched release:
mvn dependency:tree -Dincludes=org.opencastprojectHow to Check if You Are Affected
To determine whether your Java application is affected by CVE-2020-5206, inspect your build dependencies using the Maven Dependency Plugin:
mvn dependency:tree -Dincludes=org.opencastprojectAnalyze the terminal output to locate any version of Opencast kernel in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 7.6), your application is affected.
Note: The mvn dependency:tree -Dincludes=org.opencastproject command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-285: Improper Authorization, where the product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. In Opencast kernel, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2020-5206 Affected Opencast kernel Versions
2 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
org.opencastproject:opencast-kernel
|
Maven |
< 7.6
|
7.6
|
|
org.opencastproject:opencast-kernel
|
Maven |
≥ 8.0
< 8.1
|
8.1
|
References
Frequently Asked Questions
What is CVE-2020-5206?
Which Opencast kernel versions are affected?
What version fixes CVE-2020-5206?
Is opencast-kernel affected?
What is the CVSS score of CVE-2020-5206?
What CWE is associated with CVE-2020-5206?
How can I check Maven dependencies for CVE-2020-5206?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-vmm6-w4cf-7f3x",
"modified" : "2021-10-20T18:03:07Z",
"published" : "2020-01-30T21:21:30Z",
"aliases" : [ "CVE-2020-5206" ],
"summary" : "Authentication Bypass For Endpoints With Anonymous Access in Opencast",
"details" : "### Impact\n\nUsing a remember-me cookie with an arbitrary username can cause Opencast to assume proper authentication for that user even if the remember-me cookie was incorrect given that the attacked endpoint also allows anonymous access.\n\nThis way, an attacker can, for example, fake a remember-me token, assume the identity of the global system administrator and request non-public content from the search service without ever providing any proper authentication.\n\n\n### Patches\n\nThis problem is fixed in Opencast 7.6 and Opencast 8.1\n\n\n### Workarounds\n\nAs a workaround for older, unpatched versions, disabling remember-me cookies in `etc/security/mh_default_org.xml` will mitigate the problem but will obviously also disable this feature without obvious indication. To deactivate this, remove the following line from the security configuration:\n\n```xml\n<sec:remember-me … />\n```\n\n### References\n\n- [Remember-me cookie in the security configuration file](https://github.com/opencast/opencast/blob/161ee619382f144dc35eea211fc6b556025b98e1/etc/security/mh_default_org.xml#L335-L336)\n\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n\n- Open an issue in [opencast/opencast](https://github.com/opencast/opencast/issues)\n- For security-relevant information, email us at security@opencast.org",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Maven",
"name" : "org.opencastproject:opencast-kernel"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "7.6"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Maven",
"name" : "org.opencastproject:opencast-kernel"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "8.0"
}, {
"fixed" : "8.1"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/opencast/opencast/security/advisories/GHSA-vmm6-w4cf-7f3x"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-5206"
}, {
"type" : "WEB",
"url" : "https://github.com/opencast/opencast/commit/b157e1fb3b35991ca7bf59f0730329fbe7ce82e8"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-285" ],
"severity" : "CRITICAL",
"github_reviewed" : true,
"github_reviewed_at" : "2020-01-30T21:13:52Z",
"nvd_published_at" : null
}
}