Insecure deployment in Apache Solr Backup/Restore APIs

1) Arbitrary file upload

EUVDB-ID: #VU86635

Risk: Medium

CVSSv3.1: 7 [CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C]

CVE-ID: CVE-2023-50386

CWE-ID: CWE-434 - Unrestricted Upload of File with Dangerous Type

Exploit availability: Yes

Description

The vulnerability allows a remote user to compromise vulnerable system.

The vulnerability exists due to Solr ConfigSets accepts Java ".jar" and ".class" files to be uploaded through the ConfigSets API. Such files can be later included into a backup and executed during the restore procedure. When backing up Solr Collections, these configSet files would be saved to disk when using the LocalFileSystemRepository (the default for backups). If the backup was saved to a directory that Solr uses in its ClassPath/ClassLoaders, then the jar and class files would be available to use with any ConfigSet, trusted or untrusted. As a result, a remote user with backup permissions can include malicious files into the backup and execute arbitrary code on the system, when files are restored from the backup.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Apache Solr: 6.0 - 9.4.0

External links

http://lists.apache.org/thread/x4loddrb08dvkyp4c980w0yybklzof36

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, a fully functional exploit for this vulnerability is available.