DSpace has a possible Path Traversal Vulnerability in its Curation Task Reporter output path

Overview

The Curation Task feature allows an output path to be used by the reporter (-r parameter), typically used to stream results and status of curation task operations. It is not restricted to any particular base path, meaning that any path writable by the DSpace (often 'tomcat') user is allowed. This constitutes a Path Traversal Vulnerability in the curate script.

This was not a real problem when curation tasks could only be run from the command-line as a system administrator, but now that Collection/Community/Site Administrators can also run curation tasks via the web user interface, it introduces a possibility for an attacker with DSpace administrative credentials to set command parameters in such a way that output ends up in an unexpected location (for example, static resources folder in the Spring boot webapp, or overwriting a configuration file).

This vulnerability impacts DSpace versions <= 7.6.6, 8.0 <= 8.3, 9.0 <= 9.2. The attacker MUST already have DSpace Collection/Community/Site Administrator credentials in order to perform the attack.

Expected behaviour : Only a set of configured output directories should be allowed as base paths for Curation reporter output. The fix applied here is designed to be used with other systems that need to read or write streams on disk. In addition, we do not see a need for the web-managed processes to allow the -r reporter output parameter at all.

Impact

The ability to overwrite a file in /dspace/config or /dspace/bin is not desired, and could result in a denial of service attack. To actually use the curation reporter to perform an attack that escalates privileges, either a custom curation task would be needed (these can only be deployed by a system administrator), or the output would have to contain some executable information that is combined with other attacks, as a way to provide a payload in a local path.

Patches

The fix is included in DSpace 7.6.7, 8.4, 9.3 and 10.0. Please upgrade to one of these versions at the earliest convenience

If users cannot upgrade immediately, it is possible to manually patch their DSpace backend. (No changes are necessary to the frontend.) A pull request exists which can be used to patch systems running DSpace 7.6.x, 8.x or 9.x.

• Pull request for 9.x: https://github.com/DSpace/DSpace/pull/12552 (Downloadable patch file)
  • This 9.x patch file also resolves a similar path traversal vulnerability in LDN messages
• Pull request for 8.x: https://github.com/DSpace/DSpace/pull/12540 (Downloadable patch file)
  • This 8.x patch file also resolves a similar path traversal vulnerability in LDN messages
• Pull request for 7.x: https://github.com/DSpace/DSpace/pull/12539 (Downloadable patch file)

Apply the patch to a user's DSpace

If at all possible, DSpace maintainers recommend disabling the ORE Crosswalk (see below) or upgrading users' DSpace site based on the upgrade instructions. However, if usersare unable to do so, they can manually apply the above patches to their DSpace backend as follows:

1. Download the appropriate patch file to the machine where DSpace backend is running
2. From the [dspace-src] folder, apply the patch, e.g. git apply [name-of-file].patch
3. Now, update the DSpace site (based loosely on the Upgrade instructions). This generally involves three steps:
   1. Rebuild DSpace, e.g. mvn -U clean package (This will recompile all DSpace backend code)
   2. Redeploy DSpace, e.g. ant update (This will copy all newly built code to a project's installation directory). Depending on the user's setup they also may need to copy the updated "server" webapp over to their Tomcat webapps folder.
   3. Restart Tomcat (or runnable JAR)

Workarounds

Patching the system is the recommended fix. However, if users cannot patch their system immediately, it is possible to temporarily disable all Curation Tasks by commenting out every CurationTask plugin in their curate.cfg file:

# For example, ensure every line that starts with "plugin.named.org.dspace.curate.CurationTask" is commented out

#plugin.named.org.dspace.curate.CurationTask = org.dspace.ctask.general.NoOpCurationTask = noop
#plugin.named.org.dspace.curate.CurationTask = org.dspace.ctask.general.ProfileFormats = profileformats
#plugin.named.org.dspace.curate.CurationTask = org.dspace.ctask.general.RequiredMetadata = requiredmetadata
#plugin.named.org.dspace.curate.CurationTask = org.dspace.ctask.general.ClamScan = vscan
...

Please be aware that commenting out all Curation Tasks will ensure that no curation tasks can be run from either the User Interface (in various admin tools) or from the command line. So, before commenting out these lines, ensure that users do not automatically run specific curation tasks (via dspace curate command) from scheduled cron jobs or similar.

Credits

Discovered & reported by Pablo Picurelli Ortiz (@superpegaso2703), cybersecurity student at Universidad Rey Juan Carlos. Code fix developed by Kim Shepherd (@kshepherd) of The Library Code