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Linux security flaw could let VPN connections be hacked

(Image credit: Image Source: Profit_Image / Shutterstock)

The Breakpointing Bad cybersecurity research team from the University of New Mexico discovered and reported on a security flaw which could allow malicious actors to hack Virtual Private Network (VPN) connections.

William J. Tolley, Beau Kujath, and Jedidiah R. Crandall said the flaw impacts Linux, Android, macOS and other Unix-based operating systems and could allow attackers to sniff, hijack and tamper with VPN-tunnelled connections. The vulnerability was named CVE-2019-14899, with the researchers claiming it takes advantage of how operating systems handle unexpected network probes.

For the attack to be successful, the hacker needs to “determine if another user is connected to a VPN, the virtual IP address they have been assigned by the VPN server, and whether or not there is an active connection to a given website." That can be achieved either by the attacker being on the same network as the victim, or through a malicious access point or router.

The researchers also say they were able to identify the right packet sequence in some VPN connections.

"This allows us to inject data into the TCP stream and hijack connections," said William J. Tolley.

Here is the full list of the affected operating systems:

  • Ubuntu 19.10 (systemd)
  • Fedora (systemd)
  • Debian 10.2 (systemd)
  • Arch 2019.05 (systemd)
  • Manjaro 18.1.1 (systemd)
  • Devuan (sysV init)
  • MX Linux 19 (Mepis+antiX)
  • Void Linux (runit)
  • Slackware 14.2 (rc.d)
  • Deepin (rc.d)
  • FreeBSD (rc.d)
  • OpenBSD (rc.d)

Technical details of the flaw can be found on this link.