Log in Start free

Vulnerability · Published Dec 14, 2021 · Assigned by GitHub_M

CVE-2021-43821Files Accessible to External Parties in Opencast

Critical 9.9

In plain English

A critical-severity security flaw in opencast from opencast. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 2.0% (higher than 81% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.9Critical
Exploit odds (30 days)2.0%top 18.9% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack tooling1Public PoC

Official description

Opencast is an Open Source Lecture Capture & Video Management for Education. Opencast before version 9.10 or 10.6 allows references to local file URLs in ingested media packages, allowing attackers to include local files from Opencast's host machines and making them available via the web interface. Before Opencast 9.10 and 10.6, Opencast would open and include local files during ingests. Attackers could exploit this to include most local files the process has read access to, extracting secrets from the host machine. An attacker would need to have the privileges required to add new media to exploit this. But these are often widely given. The issue has been fixed in Opencast 10.6 and 11.0. You can mitigate this issue by narrowing down the read access Opencast has to files on the file system using UNIX permissions or mandatory access control systems like SELinux. This cannot prevent access to files Opencast needs to read though and we highly recommend updating.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Mavenorg.opencastproject:opencast-ingest-service-impl10.6GHSA-59g4-hpg3-3gcp

Affected products (as reported)

VendorProductVersions
opencast opencast < 10.6

Weakness: CWE-552 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

References