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Nat Slipstreaming v2.0 allows an attacker to remotely access any TCP/UDP service

8 hours ago
  • #network-security
  • #browser-exploit
  • #nat-bypass
  • NAT Slipstreaming enables attackers to remotely access any TCP/UDP service behind a victim's NAT by exploiting browser vulnerabilities and NAT ALGs.
  • It bypasses NAT/firewalls by using the victim's browser to trigger the NAT's Application Level Gateway (ALG) to open ports.
  • The attack involves extracting the victim's internal IP via WebRTC or timing attacks, controlling packet boundaries, and sending crafted SIP or other protocol packets.
  • Attackers can force packet fragmentation to position malicious data at packet boundaries, tricking NATs into opening arbitrary ports.
  • The technique is a modernized version of the 2010 NAT Pinning attack, targeting SIP and other ALG-supported protocols.
  • Proof-of-concept code is available on GitHub, demonstrating the attack across major browsers.
  • The attack requires NAT/firewall support for ALGs, commonly enabled for protocols like SIP, FTP, and H.323.
  • It leverages TURN authentication for UDP-based attacks and precise packet size control via MTU and TCP MSS manipulation.
  • Successful execution allows attackers to connect to any TCP/UDP service on the victim's machine without their knowledge.