- Vulnerability/
- USN-6561-1
USN-6561-1: libssh vulnerability
First published: Tue Dec 19 2023(Updated: )
Fabian Bäumer, Marcus Brinkmann, Jörg Schwenk discovered that the SSH protocol was vulnerable to a prefix truncation attack. If a remote attacker was able to intercept SSH communications, extension negotiation messages could be truncated, possibly leading to certain algorithms and features being downgraded. This issue is known as the Terrapin attack. This update adds protocol extensions to mitigate this issue.
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Reference Links
Frequently Asked Questions
What is the severity of USN-6561-1?
The severity of USN-6561-1 is classified as high due to potential exploitation by remote attackers.
How do I fix USN-6561-1?
To fix USN-6561-1, update the libssh-4 package to the recommended versions provided in the advisory.
What versions of Ubuntu are affected by USN-6561-1?
USN-6561-1 affects Ubuntu versions 23.10, 23.04, 22.04, and 20.04.
What attack does USN-6561-1 address?
USN-6561-1 addresses a prefix truncation attack that can compromise SSH communications.
Who discovered the vulnerability in USN-6561-1?
The vulnerability in USN-6561-1 was discovered by researchers Fabian Bäumer, Marcus Brinkmann, and Jörg Schwenk.
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