Linux

48338 readers

458 users here now

From Wikipedia, the free encyclopedia

Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).

Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.

Rules

Posts must be relevant to operating systems running the Linux kernel. GNU/Linux or otherwise.
No misinformation
No NSFW content
No hate speech, bigotry, etc

Related Communities

Community icon by Alpár-Etele Méder, licensed under CC BY 3.0

founded 5 years ago

MODERATORS

[email protected]

SSH protects the world’s most sensitive networks. It just got a lot weaker (arstechnica.com)

submitted 11 months ago by [email protected] to c/[email protected]

31 comments fedilink hide all child comments

you are viewing a single comment's thread
view the rest of the comments

[–] [email protected] 0 points 11 months ago (1 children)

This is the best summary I could come up with:

Once in place, this piece of dedicated hardware surreptitiously inhaled thousands of user names and passwords before it was finally discovered.

Ylönen, who at the time knew little about implementing strong cryptography in code, set out to develop the Secure Shell Protocol (SSH) in early 1995, about three months after the discovery of the password sniffer.

As one of the first network tools to route traffic through an impregnable tunnel fortified with a still-esoteric feature known as "public key encryption," SSH quickly caught on around the world.

Today, it’s hard to overstate the importance of the protocol, which underpins the security of apps used inside millions of organizations, including cloud environments crucial to Google, Amazon, Facebook, and other large companies.

Now, nearly 30 years later, researchers have devised an attack with the potential to undermine, if not cripple, cryptographic SSH protections that the networking world takes for granted.

The attack targets the BPP, short for Binary Packet Protocol, which is designed to ensure that adversaries with an active position can't add or drop messages exchanged during the handshake.

The original article contains 658 words, the summary contains 178 words. Saved 73%. I'm a bot and I'm open source!

[–] [email protected] 10 points 11 months ago (1 children)

you missed this part:

For Terrapin to be viable, the connection it interferes with also must be secured by either "ChaCha20-Poly1305" or "CBC with Encrypt-then-MAC," both of which are cipher modes added to the SSH protocol (in 2013 and 2012, respectively). A scan performed by the researchers found that 77 percent of SSH servers exposed to the Internet support at least one of the vulnerable encryption modes, while 57 percent of them list a vulnerable encryption mode as the preferred choice.

[–] [email protected] 5 points 11 months ago* (last edited 11 months ago)

Also that in order to exploit this it requires an active man in the middle. Which requires any of the following:

Reverse proxy hijack/NAT hijack - from a compromised machine near the server
BGP hijack - stealing traffic to the real IP
DNS hijack - stealing traffic to send to a different IP
Malicious/compromised network transit
Local network gateway control
WAP poisoning - wifi roaming is designed really well so this is actually easier than it sounds.

Almost all of those have decent mitigations like 801.x and BGP monitoring. The best mitigation is that you can just change your client config to disable those ciphersuites though.