[+] Credits: John Page aka hyp3rlinx [+] Website: hyp3rlinx.altervista.org [+] Source: http://hyp3rlinx.altervista.org/advisories/APACHE-COUCHDB-LOCAL-PRIVILEGE-ESCALATION.txt [+] ISR: ApparitionSec Vendor: ================== couchdb.apache.org Product: ============== CouchDB v2.0.0 Apache CouchDB is open source database software that focuses on ease of use and having an architecture. It has a document-oriented NoSQL database architecture and is implemented in the concurrency-oriented language Erlang; it uses JSON to store data, JavaScript as its query language using MapReduce, and HTTP for an API. Vulnerability Type: =================== Privilege Escalation (Insecure File Permissions) CVE Reference: ============== N/A Vulnerability Details: ===================== CouchDB sets weak file permissions potentially allowing 'Standard' Windows users to elevate privileges. The "nssm.exe" (Apache CouchDB) executable can be replaced by a 'Standard' non administrator user, allowing them to add a backdoor Administrator account once the "Apache CouchDB" service is restarted or system rebooted. As Apache CouchDB runs as LOCALSYSTEM, standard users can now execute arbitrary code with the privileges of the SYSTEM. Issue is the 'C' flag (Change) for 'Authenticated Users' group. e.g. c:\CouchDB>cacls * | findstr Users BUILTIN\Users:(OI)(CI)(ID)R NT AUTHORITY\Authenticated Users:(ID)C NT AUTHORITY\Authenticated Users:(OI)(CI)(IO)(ID)C BUILTIN\Users:(OI)(CI)(ID)R NT AUTHORITY\Authenticated Users:(ID)C NT AUTHORITY\Authenticated Users:(OI)(CI)(IO)(ID)C BUILTIN\Users:(OI)(CI)(ID)R NT AUTHORITY\Authenticated Users:(ID)C NT AUTHORITY\Authenticated Users:(OI)(CI)(IO)(ID)C c:\CouchDB>sc qc "Apache CouchDB" [SC] QueryServiceConfig SUCCESS SERVICE_NAME: Apache CouchDB TYPE : 10 WIN32_OWN_PROCESS START_TYPE : 3 DEMAND_START ERROR_CONTROL : 1 NORMAL BINARY_PATH_NAME : C:\CouchDB\bin\nssm.exe LOAD_ORDER_GROUP : TAG : 0 DISPLAY_NAME : Apache CouchDB DEPENDENCIES : SERVICE_START_NAME : LocalSystem Exploitation Technique: ======================= Local Severity Level: ================ Medium [+] Disclaimer The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise. Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by reformatting it, and that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided that due credit is given to the author. The author is not responsible for any misuse of the information contained herein and accepts no responsibility for any damage caused by the use or misuse of this information. The author prohibits any malicious use of security related information or exploits by the author or elsewhere. hyp3rlinx