Unpatched RCE Vulnerability in LibreOffice Let Hackers Take Complete Control Of Your Computer

The researcher discovered a code execution vulnerability in LibreOffice let an attacker hack your computer by just sending a weaponized document with macro and promote a user to Open it via LibreOffice.

LibreOffice is an open-source office suite alternative of MS office developed by The Document Foundation that compatible with .doc, .docx, .xls, .xlsx, .ppt, .pptx files and supports all the operating system platform.

Very recently LibreOffice patched an arbitrary script execution vulnerability ( CVE-2019-9848) that allows attackers to execute arbitrary python commands silently without warning to exploit the vulnerable system.

A researcher with the name Alex in Twitter claims that he successfully bypassed the fix of CVE-2019-9848 in LibreOffice 6.2.5.

Earlier this year, Alex also found the similar RCE vulnerability in LibreOffice that allows attackers to exploit the arbitrary code in Windows and Linux Platform.

Nils Emmerich from Insinuator found this vulnerability (CVE-2019-9848) and his research explains that a macro shipped with LibreOffice are executed without prompting the user.

The bug allows an attacker to execute the code on a vulnerable machine and exploit the system without prompting users to enable the macro.

By Default, LibreOffice shipped with LibreLogo (Python Interpreter), a macro to programmable move a turtle vector graphic to executes custom script code that is internally translated to python code and executed.

According to Emmerich, The critical bug exactly resides in the LibreLogo, in which the code is not translated well and just supplying python code as the script code often results in the same code after translation.

A proof of concept where he explained the method to exploit the bug by placing the content, in which Run is a hyperlink executing LibreLogo:run on a mouseover event.

In this PoC explains that the code simply executed without prompt to the user asking to run the code and it is even possible to get code execution  Using forms and the OnFocus event without mouseover event.

Since Alex reported his new bug, LibreOffice Team still working to fix the vulnerability, until then users recommend disabling the LibreLogo component in the current version of LibreOffice.

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