Vulnerabilities > CVE-2022-41961 - Origin Validation Error vulnerability in Bigbluebutton 2.4
BigBlueButton is an open source web conferencing system. Versions prior to 2.4-rc-6 are subject to Ineffective user bans. The attacker could register multiple users, and join the meeting with one of them. When that user is banned, they could still join the meeting with the remaining registered users from the same extId. This issue has been fixed by improving permissions such that banning a user removes all users related to their extId, including registered users that have not joined the meeting. This issue is patched in versions 2.4-rc-6 and 2.5-alpha-1. There are no workarounds.
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Cache Poisoning An attacker exploits the functionality of cache technologies to cause specific data to be cached that aids the attackers' objectives. This describes any attack whereby an attacker places incorrect or harmful material in cache. The targeted cache can be an application's cache (e.g. a web browser cache) or a public cache (e.g. a DNS or ARP cache). Until the cache is refreshed, most applications or clients will treat the corrupted cache value as valid. This can lead to a wide range of exploits including redirecting web browsers towards sites that install malware and repeatedly incorrect calculations based on the incorrect value.
- DNS Cache Poisoning A domain name server translates a domain name (such as www.example.com) into an IP address that Internet hosts use to contact Internet resources. An attacker modifies a public DNS cache to cause certain names to resolve to incorrect addresses that the attacker specifies. The result is that client applications that rely upon the targeted cache for domain name resolution will be directed not to the actual address of the specified domain name but to some other address. Attackers can use this to herd clients to sites that install malware on the victim's computer or to masquerade as part of a Pharming attack.
- Exploitation of Session Variables, Resource IDs and other Trusted Credentials Attacks on session IDs and resource IDs take advantage of the fact that some software accepts user input without verifying its authenticity. For example, a message queuing system that allows service requesters to post messages to its queue through an open channel (such as anonymous FTP), authorization is done through checking group or role membership contained in the posted message. However, there is no proof that the message itself, the information in the message (such group or role membership), or indeed the process that wrote the message to the queue are authentic and authorized to do so. Many server side processes are vulnerable to these attacks because the server to server communications have not been analyzed from a security perspective or the processes "trust" other systems because they are behind a firewall. In a similar way servers that use easy to guess or spoofable schemes for representing digital identity can also be vulnerable. Such systems frequently use schemes without cryptography and digital signatures (or with broken cryptography). Session IDs may be guessed due to insufficient randomness, poor protection (passed in the clear), lack of integrity (unsigned), or improperly correlation with access control policy enforcement points. Exposed configuration and properties files that contain system passwords, database connection strings, and such may also give an attacker an edge to identify these identifiers. The net result is that spoofing and impersonation is possible leading to an attacker's ability to break authentication, authorization, and audit controls on the system.
- Application API Message Manipulation via Man-in-the-Middle An attacker manipulates either egress or ingress data from a client within an application framework in order to change the content of messages. Performing this attack can allow the attacker to gain unauthorized privileges within the application, or conduct attacks such as phishing, deceptive strategies to spread malware, or traditional web-application attacks. The techniques require use of specialized software that allow the attacker to man-in-the-middle communications between the web browser and the remote system. Despite the use of MITM software, the attack is actually directed at the server, as the client is one node in a series of content brokers that pass information along to the application framework. Additionally, it is not true "Man-in-the-Middle" attack at the network layer, but an application-layer attack the root cause of which is the master applications trust in the integrity of code supplied by the client.