In cooperation with the university Paderborn and Münster University of Applied Sciences, we discovered a new flaw in the specification of TLS. The vulnerability is called ALPACA and exploits a weakness in the authentication of TLS for cross-protocol attacks. The attack allows an attacker to steal cookies or perform cross-site-scripting (XSS) if the specific conditions for the attack are met.
TLS is an internet standard to secure the communication between servers and clients on the internet, for example that of web servers, FTP servers, and Email servers. This is possible because TLS was designed to be application layer independent, which allows its use in many diverse communication protocols.
ALPACA is an application layer protocol content confusion attack, exploiting TLS servers implementing different protocols but using compatible certificates, such as multi-domain or wildcard certificates. Attackers can redirect traffic from one subdomain to another, resulting in a valid TLS session. This breaks the authentication of TLS and cross-protocol attacks may be possible where the behavior of one protocol service may compromise the other at the application layer.
We investigate cross-protocol attacks on TLS in general and conducted a systematic case study on web servers, redirecting HTTPS requests from a victim's web browser to SMTP, IMAP, POP3, and FTP servers. We show that in realistic scenarios, the attacker can extract session cookies and other private user data or execute arbitrary JavaScript in the context of the vulnerable web server, therefore bypassing TLS and web application security.
We evaluated the real-world attack surface of web browsers and widely-deployed Email and FTP servers in lab experiments and with internet-wide scans. We find that 1.4M web servers are generally vulnerable to cross-protocol attacks, i.e., TLS application data confusion is possible. Of these, 114k web servers can be attacked using an exploitable application server. As a countermeasure, we propose the use of the Application Layer Protocol Negotiation (ALPN) and Server Name Indication (SNI) extensions in TLS to prevent these and other cross-protocol attacks.
Although this vulnerability is very situational and can be challenging to exploit, there are some configurations that are exploitable even by a pure web attacker. Furthermore, we could only analyze a limited number of protocols, and other attack scenarios may exist. Thus, we advise that administrators review their deployments and that application developers (client and server) implement countermeasures proactively for all protocols.
More information on ALPACA can be found on the website https://alpaca-attack.com/.
More information- Underground Hacker Sites
- Free Pentest Tools For Windows
- Pentest Tools Open Source
- Hacking Tools For Mac
- Hacker Techniques Tools And Incident Handling
- Hacker Tools Apk Download
- Hack Tools
- Hacking Tools Pc
- Pentest Tools For Ubuntu
- Hacking Apps
- World No 1 Hacker Software
- Pentest Tools Windows
- Pentest Tools For Windows
- Pentest Tools
- Wifi Hacker Tools For Windows
- Hacker Search Tools
- Bluetooth Hacking Tools Kali
- Install Pentest Tools Ubuntu
- Nsa Hack Tools Download
- Hacking Tools Online
- Github Hacking Tools
- Hacker Tools Apk Download
- Game Hacking
- Hack Rom Tools
- Hack Tools For Windows
- Pentest Tools Open Source
- Hacker Tools Software
- Pentest Tools Website
- Hacking Tools Pc
- How To Install Pentest Tools In Ubuntu
- Kik Hack Tools
- Hack Tools For Mac
- Tools Used For Hacking
- Blackhat Hacker Tools
- Hacking Tools And Software
- Tools 4 Hack
- Hacking Tools Name
- Hacker Security Tools
- Pentest Tools For Android
- Bluetooth Hacking Tools Kali
- Hacking Tools Pc
- Hacking Tools And Software
- Hacker Tools Software
- Hacker Tools For Pc
- Hacking Tools 2019
- What Is Hacking Tools
- Nsa Hacker Tools
- Blackhat Hacker Tools
- Hackers Toolbox
- Hackrf Tools
- Pentest Tools Github
- Hacking Tools Name
- Hack Tools
- Pentest Tools Linux
- Easy Hack Tools
- Pentest Tools Port Scanner
- Hack Tool Apk
- Hacking Tools Windows
- Hacker Techniques Tools And Incident Handling
- Hack Website Online Tool
- Hacking Tools Github
- Pentest Tools Online
- Hackers Toolbox
- Hacking Tools 2019
- Hacking Tools Windows
- Hack Tools For Games
- Pentest Tools Find Subdomains
- Hack Tools 2019
- Install Pentest Tools Ubuntu
- Pentest Tools Linux
- Pentest Tools Download
- Install Pentest Tools Ubuntu
- Pentest Tools Bluekeep
- Pentest Tools Open Source
- Hacker Tools 2019
- Tools 4 Hack
- Hacking Tools Windows
- Hacking Tools Hardware
- Pentest Tools Port Scanner
- Hacking Tools For Windows 7
- Hacking Tools 2019
- Hack Tools Mac
- Underground Hacker Sites
- Nsa Hack Tools Download
- Hack Rom Tools
- Pentest Tools For Windows
- Best Pentesting Tools 2018
- Hacker Tools
- Hack Tools For Windows
- Hacking Tools Windows 10
- Hacker Tools Apk
- Hacker Tools Github
- Hack And Tools
- Hacking Tools Download
- Computer Hacker
- Hacker Tools Free
- Hack Tools Pc
- Hacking Tools 2019
- Hack Rom Tools
- Hacking Tools For Beginners
- How To Make Hacking Tools
- Android Hack Tools Github
- Pentest Tools For Android
- Pentest Tools Url Fuzzer
- Bluetooth Hacking Tools Kali
- Pentest Tools Apk
- Hacking Tools Mac
- Hack Tool Apk
- Hacker
- Hack And Tools
- Hack Tools For Windows
- Hacker Tools For Ios
- Easy Hack Tools
- New Hacker Tools
- Underground Hacker Sites
- Pentest Automation Tools
- Pentest Automation Tools
- Black Hat Hacker Tools
- World No 1 Hacker Software
- Usb Pentest Tools
- Hacker Tools 2019
- Pentest Tools Download
- Hacking Tools For Kali Linux
- Computer Hacker
- Hacking Apps
- Hacking Tools Usb
- Pentest Tools Online
- Hack Apps
- Hacking Tools For Games
- Pentest Tools Kali Linux
- Hack Tools Github
- How To Hack
- Hacking Tools Mac
- Hack Apps
- Growth Hacker Tools
- Hacker Tools Apk
- Pentest Tools Subdomain
- Hacking Tools Mac
- Hacker Techniques Tools And Incident Handling
- Pentest Tools For Mac
- Usb Pentest Tools
- Bluetooth Hacking Tools Kali
- Hacker Tools For Windows
- Hack Website Online Tool
- Pentest Tools Free
- Pentest Tools Framework
- Hacker Techniques Tools And Incident Handling
- Hacking Tools Online