Know every vulnerabilitybefore it knows you.
DevGuard continuously monitors your dependencies and alerts you when CVEs like this one affect your stack — with real-time threat intelligence built for developers.
GHSA-mh8g-hprg-8363
No affected components available
Impact
The security configuration in etc/security/mh_default_org.xml enables a remember-me cookie based on a hash created from the username, password, and an additional system key. Opencast has hard-coded this system key in the large XML file and never mentions to change this, basically ensuring that all systems use the same key:
<sec:remember-me key="opencast" user-service-ref="userDetailsService" />
This means that an attacker getting access to a remember-me token for one server can get access to all servers which allow log-in using the same credentials without ever needing the credentials. For example, a remember-me token obtained from develop.opencast.org can be used on stable.opencast.org without actually knowing the log-in credentials.
Such an attack will usually not work on different installations – assuming that safe, unique passwords are used – but it is basically guaranteed to work to get access to all machines of one cluster if a token from one machine is compromised.
Patches
This problem is fixed in Opencast 7.6 and Opencast 8.1
Workarounds
We strongly recommend updating to the patched version. Still, as a workaround for older versions, in etc/security/mh_default_org.xml, set a custom key for each server:
<sec:remember-me key="CUSTOM_RANDOM_KEY" user-service-ref="userDetailsService" />
References
- Relevant lines in the security configuration
- Spring Security Remember-Me Authentication Documentation
For more information
If you have any questions or comments about this advisory:
- Open an issue in opencast/opencast
- For security-relevant information, email us at security@opencast.org
Thanks
Thanks to @LukasKalbertodt for reporting the issue.
The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker needs basic access or low-level privileges. The attacker needs the user to perform some action, like clicking a link. The vulnerability can affect other systems as well, not just the initial system. There is a high impact on the confidentiality of the information.
Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.
The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.
We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.
Browse More
Continuously monitor your dependencies and get alerted when vulnerabilities like this one affect your stack.
Checkout DevGuard