CVE-2017-12629

Remote code execution occurs in Apache Solr before 7.1 with Apache Lucene before 7.1 by exploiting XXE in conjunction with use of a Config API add-listener command to reach the RunExecutableListener class. Elasticsearch, although it uses Lucene, is NOT vulnerable to this. Note that the XML external entity expansion vulnerability occurs in the XML Query Parser which is available, by default, for any query request with parameters deftype=xmlparser and can be exploited to upload malicious data to the /upload request handler or as Blind XXE using ftp wrapper in order to read arbitrary local files from the Solr server. Note also that the second vulnerability relates to remote code execution using the RunExecutableListener available on all affected versions of Solr.

Weakness

The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.

Affected Software

Extended Description

XML documents optionally contain a Document Type Definition (DTD), which, among other features, enables the definition of XML entities. It is possible to define an entity by providing a substitution string in the form of a URI. The XML parser can access the contents of this URI and embed these contents back into the XML document for further processing. By submitting an XML file that defines an external entity with a file:// URI, an attacker can cause the processing application to read the contents of a local file. For example, a URI such as “file:///c:/winnt/win.ini” designates (in Windows) the file C:\Winnt\win.ini, or file:///etc/passwd designates the password file in Unix-based systems. Using URIs with other schemes such as http://, the attacker can force the application to make outgoing requests to servers that the attacker cannot reach directly, which can be used to bypass firewall restrictions or hide the source of attacks such as port scanning. Once the content of the URI is read, it is fed back into the application that is processing the XML. This application may echo back the data (e.g. in an error message), thereby exposing the file contents.

Potential Mitigations

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/221.html

References

• http://mail-archives.us.apache.org/mod_mbox/www-announce/201710.mbox/%3CCAOOKt51UO_6Vy%3Dj8W%3Dx1pMbLW9VJfZyFWz7pAnXJC_OAdSZubA%40mail.gmail.com%3E
• http://openwall.com/lists/oss-security/2017/10/13/1
• http://www.securityfocus.com/bid/101261
• https://access.redhat.com/errata/RHSA-2017:3123
• https://access.redhat.com/errata/RHSA-2017:3124
• https://access.redhat.com/errata/RHSA-2017:3244
• https://access.redhat.com/errata/RHSA-2017:3451
• https://access.redhat.com/errata/RHSA-2017:3452
• https://access.redhat.com/errata/RHSA-2018:0002
• https://access.redhat.com/errata/RHSA-2018:0003
• https://access.redhat.com/errata/RHSA-2018:0004
• https://access.redhat.com/errata/RHSA-2018:0005
• https://lists.apache.org/thread.html/r140128dc6bb4f4e0b6a39e962c7ca25a8cbc8e48ed766176c931fccc%40%3Cusers.solr.apache.org%3E
• https://lists.apache.org/thread.html/r26c996b068ef6c5e89aa59acb769025cfd343a08e63fbe9e7f3f720f%40%3Coak-issues.jackrabbit.apache.org%3E
• https://lists.apache.org/thread.html/r3da74965aba2b5f5744b7289ad447306eeb2940c872801819faa9314%40%3Cusers.solr.apache.org%3E
• https://lists.apache.org/thread.html/r95df34bb158375948da82b4dfe9a1b5d528572d586584162f8f5aeef%40%3Cusers.solr.apache.org%3E
• https://lists.debian.org/debian-lts-announce/2018/01/msg00028.html
• https://s.apache.org/FJDl
• https://twitter.com/ApacheSolr/status/918731485611401216
• https://twitter.com/joshbressers/status/919258716297420802
• https://twitter.com/searchtools_avi/status/918904813613543424
• https://usn.ubuntu.com/4259-1/
• https://www.debian.org/security/2018/dsa-4124
• https://www.exploit-db.com/exploits/43009/