• Home
  • Cyber Crime
  • Cyber warfare
  • APT
  • Data Breach
  • Deep Web
  • Digital ID
  • Hacking
  • Hacktivism
  • Intelligence
  • Internet of Things
  • Laws and regulations
  • Malware
  • Mobile
  • Reports
  • Security
  • Social Networks
  • Terrorism
  • ICS-SCADA
  • POLICIES
  • Contact me
MUST READ

U.S. CISA urges FCEB agencies to fix two Microsoft SharePoint flaws immediately and added them to its Known Exploited Vulnerabilities catalog

 | 

Sophos fixed two critical Sophos Firewall vulnerabilities

 | 

French Authorities confirm XSS.is admin arrested in Ukraine

 | 

Microsoft linked attacks on SharePoint flaws to China-nexus actors

 | 

Cisco confirms active exploitation of ISE and ISE-PIC flaws

 | 

SharePoint under fire: new ToolShell attacks target enterprises

 | 

CrushFTP zero-day actively exploited at least since July 18

 | 

Hardcoded credentials found in HPE Aruba Instant On Wi-Fi devices

 | 

MuddyWater deploys new DCHSpy variants amid Iran-Israel conflict

 | 

U.S. CISA urges to immediately patch Microsoft SharePoint flaw adding it to its Known Exploited Vulnerabilities catalog

 | 

Microsoft issues emergency patches for SharePoint zero-days exploited in "ToolShell" attacks

 | 

SharePoint zero-day CVE-2025-53770 actively exploited in the wild

 | 

Singapore warns China-linked group UNC3886 targets its critical infrastructure

 | 

U.S. CISA adds Fortinet FortiWeb flaw to its Known Exploited Vulnerabilities catalog

 | 

SECURITY AFFAIRS MALWARE NEWSLETTER ROUND 54

 | 

Security Affairs newsletter Round 533 by Pierluigi Paganini – INTERNATIONAL EDITION

 | 

Radiology Associates of Richmond data breach impacts 1.4 million people

 | 

Fortinet FortiWeb flaw CVE-2025-25257 exploited hours after PoC release

 | 

Authorities released free decryptor for Phobos and 8base ransomware

 | 

Anne Arundel Dermatology data breach impacts 1.9 million people

 | 
  • Home
  • Cyber Crime
  • Cyber warfare
  • APT
  • Data Breach
  • Deep Web
  • Digital ID
  • Hacking
  • Hacktivism
  • Intelligence
  • Internet of Things
  • Laws and regulations
  • Malware
  • Mobile
  • Reports
  • Security
  • Social Networks
  • Terrorism
  • ICS-SCADA
  • POLICIES
  • Contact me
  • Home
  • Breaking News
  • Hacking
  • Old known issue in Firefox allows HTML files to steal other files from victim’s system

Old known issue in Firefox allows HTML files to steal other files from victim’s system

Pierluigi Paganini July 03, 2019

Opening an HTML file on Firefox could allow attackers to steal files stored on a victim’s computer due to a weakness in the popular web browser.

The security expert Barak Tawily demonstrated that opening an HTML file on Firefox could allow attackers to steal files stored on a victim’s computer due to a 17-year-old known bug in the browser.

The researcher published the details of the attack through TheHackerNews website and demonstrated that his technique works against the latest version of Firefox.

“Barak Tawily, an application security researcher, shared his findings with The Hacker News, wherein he successfully developed a new proof-of-concept attack against the latest version of Firefox by leveraging a 17-year-old known issue in the browser.” reported TheHackerNews.

The expert was analyzing the implementation of the Same Origin Policy in Firefox when discovered that it is vulnerable to local files theft attack.

“Recently, I was performing a research on Same Origin Policy attacks, I managed to realize that the la version of Firefox (currently 67) is vulnerable to local files theft attack (on any supported OS), due to improper implementation of Same Origin Policy for file scheme URIs. Let’s go over the PoC details then I will provide an explanation of why its not patched yet.” wrote the expert.

According to Tawily, Firefox didn’t fix the flawed implementation of the Same Origin Policy (SOP) for File URI Scheme over the years.

The expert also shared details of its PoC and a video PoC of the attack. Tawily explained how an attacker can easily steal secret SSH keys of Linux victims if they save downloaded files in the user-directory that includes SSH keys in its subfolder.

  1. Attacker sends email to victim with attachment file to be downloaded / Victim browse to malicious website and download file
  2. The victim opens the HTML malicious file
  3. The file loading the containing folder in an iframe (so my file path is file:///home/user/-malicious.html, and the iframe source will be file:///home/user/)
  4. The victim thinks he clicks on a button on the malicious HTML, but in fact he is clicking on the malicious file html inside the iframe’s directory listing (using ClickJacking technique, in order to apply the “context switching bug” which allows me access the directory listing of my containing folder)
  5. The malicious iframe now have escalated privileges and is be able to read any file on the folder contains the malicious file, (in most cases downloads folder, in my case is file:///home/user/).
  6. The malicious file is able to read any file on it’s containing folder (file:///home/user/), such as SSH private key by simply fetching the URL file:///home/user/.ssh/ida_rsa and stealing any file by 1 more fetch request to the attacker’s malicious website with the files’ content.
  7. The attacker gains all files in the folder containing the malicious file exploit this vulnerability

An attacker could successfully carry out the attack by tricking victims into downloading and opening a malicious HTML file on the Firefox web browser and into clicking on a fake button to trigger the exploit.

“Tawily told The Hacker News that all the above-mentioned actions could secretly happen in the background within seconds without the knowledge of victims, as soon as they click the button place carefully on the malicious HTML page.” continues The Hacker News

The expert reported the flaw to Mozilla, but the company seems to have no intention to fix the issue soon.

“Our implementation of the Same Origin Policy allows every file:// URL to get access to files in the same folder and subfolders.” reads the reply from Mozilla.

[adrotate banner=”9″] [adrotate banner=”12″]

Pierluigi Paganini

(SecurityAffairs – Same Origin Policy, hacking)

[adrotate banner=”5″]

[adrotate banner=”13″]


facebook linkedin twitter

Firefox Hacking hacking news information security news Mozilla Pierluigi Paganini Same Origin Policy Security Affairs Security News

you might also like

Pierluigi Paganini July 23, 2025
U.S. CISA urges FCEB agencies to fix two Microsoft SharePoint flaws immediately and added them to its Known Exploited Vulnerabilities catalog
Read more
Pierluigi Paganini July 23, 2025
Sophos fixed two critical Sophos Firewall vulnerabilities
Read more

leave a comment

newsletter

Subscribe to my email list and stay
up-to-date!

    recent articles

    U.S. CISA urges FCEB agencies to fix two Microsoft SharePoint flaws immediately and added them to its Known Exploited Vulnerabilities catalog

    Hacking / July 23, 2025

    Sophos fixed two critical Sophos Firewall vulnerabilities

    Security / July 23, 2025

    French Authorities confirm XSS.is admin arrested in Ukraine

    Cyber Crime / July 23, 2025

    Microsoft linked attacks on SharePoint flaws to China-nexus actors

    APT / July 23, 2025

    Cisco confirms active exploitation of ISE and ISE-PIC flaws

    Hacking / July 22, 2025

    To contact me write an email to:

    Pierluigi Paganini :
    pierluigi.paganini@securityaffairs.co

    LEARN MORE

    QUICK LINKS

    • Home
    • Cyber Crime
    • Cyber warfare
    • APT
    • Data Breach
    • Deep Web
    • Digital ID
    • Hacking
    • Hacktivism
    • Intelligence
    • Internet of Things
    • Laws and regulations
    • Malware
    • Mobile
    • Reports
    • Security
    • Social Networks
    • Terrorism
    • ICS-SCADA
    • POLICIES
    • Contact me

    Copyright@securityaffairs 2024

    We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. By clicking “Accept All”, you consent to the use of ALL the cookies. However, you may visit "Cookie Settings" to provide a controlled consent.
    Cookie SettingsAccept All
    Manage consent

    Privacy Overview

    This website uses cookies to improve your experience while you navigate through the website. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities...
    Necessary
    Always Enabled
    Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
    Non-necessary
    Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website.
    SAVE & ACCEPT