Lars Kiesow

13 exploits Active since Jan 2020
CVE-2021-43807 WRITEUP HIGH WRITEUP
Opencast < 9.10 - HTTP Method Spoofing via URL Parameter
Opencast is an Open Source Lecture Capture & Video Management for Education. Opencast versions prior to 9.10 allow HTTP method spoofing, allowing to change the assumed HTTP method via URL parameter. This allows attackers to turn HTTP GET requests into PUT requests or an HTTP form to send DELETE requests. This bypasses restrictions otherwise put on these types of requests and aids in cross-site request forgery (CSRF) attacks, which would otherwise not be possible. The vulnerability allows attackers to craft links or forms which may change the server state. This issue is fixed in Opencast 9.10 and 10.0. You can mitigate the problem by setting the `SameSite=Strict` attribute for your cookies. If this is a viable option for you depends on your integrations. We strongly recommend updating in any case.
CVSS 7.5
CVE-2020-26234 WRITEUP MEDIUM WRITEUP
Opencast < 7.9 - Man-in-the-Middle Attack via Disabled HTTPS Hostname Verification
Opencast before versions 8.9 and 7.9 disables HTTPS hostname verification of its HTTP client used for a large portion of Opencast's HTTP requests. Hostname verification is an important part when using HTTPS to ensure that the presented certificate is valid for the host. Disabling it can allow for man-in-the-middle attacks. This problem is fixed in Opencast 7.9 and Opencast 8.8 Please be aware that fixing the problem means that Opencast will not simply accept any self-signed certificates any longer without properly importing them. If you need those, please make sure to import them into the Java key store. Better yet, get a valid certificate.
CVSS 4.8
CVE-2020-5206 WRITEUP HIGH WRITEUP
Opencast < 7.6 - Improper Authentication via Remember-Me Cookie
In Opencast before 7.6 and 8.1, using 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. This 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. This problem is fixed in Opencast 7.6 and Opencast 8.1
CVSS 8.7
CVE-2020-5222 WRITEUP MEDIUM WRITEUP
Opencast < 7.6 - Use of Hard-coded Credentials via Remember-Me Cookie
Opencast before 7.6 and 8.1 enables a remember-me cookie based on a hash created from the username, password, and an additional system key. 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. This problem is fixed in Opencast 7.6 and Opencast 8.1
CVSS 6.8
CVE-2020-5227 WRITEUP MEDIUM WRITEUP
feedgen < 0.9.0 - XML Denial of Service via Entity Expansion
Feedgen (python feedgen) before 0.9.0 is susceptible to XML Denial of Service attacks. The *feedgen* library allows supplying XML as content for some of the available fields. This XML will be parsed and integrated into the existing XML tree. During this process, feedgen is vulnerable to XML Denial of Service Attacks (e.g. XML Bomb). This becomes a concern in particular if feedgen is used to include content from untrused sources and if XML (including XHTML) is directly included instead of providing plain tex content only. This problem has been fixed in feedgen 0.9.0 which disallows XML entity expansion and external resources.
CVSS 4.4
CVE-2020-5229 WRITEUP HIGH WRITEUP
Opencast < 8.1 - Use of Broken Cryptographic Algorithm via MD5 Password Hashing
Opencast before 8.1 stores passwords using the rather outdated and cryptographically insecure MD5 hash algorithm. Furthermore, the hashes are salted using the username instead of a random salt, causing hashes for users with the same username and password to collide which is problematic especially for popular users like the default `admin` user. This essentially means that for an attacker, it might be feasible to reconstruct a user's password given access to these hashes. Note that attackers needing access to the hashes means that they must gain access to the database in which these are stored first to be able to start cracking the passwords. The problem is addressed in Opencast 8.1 which now uses the modern and much stronger bcrypt password hashing algorithm for storing passwords. Note, that old hashes remain MD5 until the password is updated. For a list of users whose password hashes are stored using MD5, take a look at the `/user-utils/users/md5.json` REST endpoint.
CVSS 7.7
CVE-2020-5230 WRITEUP HIGH WRITEUP
Opencast < 7.6 - Path Traversal and Arbitrary File Write via Media Package Identifier
Opencast before 8.1 and 7.6 allows almost arbitrary identifiers for media packages and elements to be used. This can be problematic for operation and security since such identifiers are sometimes used for file system operations which may lead to an attacker being able to escape working directories and write files to other locations. In addition, Opencast's Id.toString(…) vs Id.compact(…) behavior, the latter trying to mitigate some of the file system problems, can cause errors due to identifier mismatch since an identifier may unintentionally change. This issue is fixed in Opencast 7.6 and 8.1.
CVSS 7.7
CVE-2020-5231 WRITEUP MEDIUM WRITEUP
Opencast < 7.6 - Improper Authorization via ROLE_COURSE_ADMIN User Creation
In Opencast before 7.6 and 8.1, users with the role ROLE_COURSE_ADMIN can use the user-utils endpoint to create new users not including the role ROLE_ADMIN. ROLE_COURSE_ADMIN is a non-standard role in Opencast which is referenced neither in the documentation nor in any code (except for tests) but only in the security configuration. From the name – implying an admin for a specific course – users would never expect that this role allows user creation. This issue is fixed in 7.6 and 8.1 which both ship a new default security configuration.
CVSS 4.8
CVE-2021-21318 WRITEUP MEDIUM WRITEUP
Opencast < 9.2 - Incorrect Authorization via Series Access Control Overwrite
Opencast is a free, open-source platform to support the management of educational audio and video content. In Opencast before version 9.2 there is a vulnerability in which publishing an episode with strict access rules will overwrite the currently set series access. This allows for an easy denial of access for all users without superuser privileges, effectively hiding the series. Access to series and series metadata on the search service (shown in media module and player) depends on the events published which are part of the series. Publishing an event will automatically publish a series and update access to it. Removing an event or republishing the event should do the same. Affected versions of Opencast may not update the series access or remove a published series if an event is being removed. On removal of an episode, this may lead to an access control list for series metadata with broader access rules than the merged access rules of all remaining events, or the series metadata still being available although all episodes of that series have been removed. This problem is fixed in Opencast 9.2.
CVSS 5.4
CVE-2021-32623 WRITEUP HIGH WRITEUP
Opencast < 9.6 - Authenticated Denial of Service via XML Entity Expansion
Opencast is a free and open source solution for automated video capture and distribution. Versions of Opencast prior to 9.6 are vulnerable to the billion laughs attack, which allows an attacker to easily execute a (seemingly permanent) denial of service attack, essentially taking down Opencast using a single HTTP request. To exploit this, users need to have ingest privileges, limiting the group of potential attackers The problem has been fixed in Opencast 9.6. There is no known workaround for this issue.
CVSS 8.1
CVE-2021-43807 WRITEUP HIGH WRITEUP
Opencast < 9.10 - HTTP Method Spoofing via URL Parameter
Opencast is an Open Source Lecture Capture & Video Management for Education. Opencast versions prior to 9.10 allow HTTP method spoofing, allowing to change the assumed HTTP method via URL parameter. This allows attackers to turn HTTP GET requests into PUT requests or an HTTP form to send DELETE requests. This bypasses restrictions otherwise put on these types of requests and aids in cross-site request forgery (CSRF) attacks, which would otherwise not be possible. The vulnerability allows attackers to craft links or forms which may change the server state. This issue is fixed in Opencast 9.10 and 10.0. You can mitigate the problem by setting the `SameSite=Strict` attribute for your cookies. If this is a viable option for you depends on your integrations. We strongly recommend updating in any case.
CVSS 7.5
CVE-2022-29237 WRITEUP MEDIUM WRITEUP
Opencast < 10.14 - Authenticated Organization Barrier Bypass via Ingest REST Interface
Opencast is a free and open source solution for automated video capture and distribution at scale. Prior to Opencast 10.14 and 11.7, users could pass along URLs for files belonging to organizations other than the user's own, which Opencast would then import into the current organization, bypassing organizational barriers. Attackers must have full access to Opencast's ingest REST interface, and also know internal links to resources in another organization of the same Opencast cluster. Users who do not run a multi-tenant cluster are not affected by this issue. This issue is fixed in Opencast 10.14 and 11.7.
CVSS 5.4
CVE-2025-55202 WRITEUP MEDIUM WRITEUP
Opencast < 17.7 - Relative Path Traversal in UI Config Module
Opencast is a free, open-source platform to support the management of educational audio and video content. In version 18.0 and versions before 17.7, the protections against path traversal attacks in the UI config module are insufficient, still partially allowing for attacks in very specific cases. The path is checked without checking for the file separator. This could allow attackers access to files within another folder which starts with the same path. This issue has been fixed in versions 17.7 and 18.1. To mitigate this issue, check for folders that start with the same path as the ui-config folder.
CVSS 5.3