OpenSSH 5.2 Secured and Tuned
Even though the OpenSSH project emphasizes that the focus of 5.2 is bug fixes to the 5.1 version, 5.2 does contain some notable enhancements.
Security-wise the new OpenSSH version replaces cipher block chaining (CBC) mode as the default cipher order with the Advanced Encryption Standard (AES) Counter (CTR) mode to remove the susceptibility to "Plaintext Recovery Attack Against SSH." The software also adds other countermeasures to these attacks, as reported in CPNI Vulnerability Advisory SSH 957037. Last November it became clear that many versions of OpenSSH exposed up to 32 bits of plaintext ciphertext to attackers when the default CBC mode was in use. The solution in 5.2 was to read the maximum supported packet length instead of terminating the connection, thereby eliminating the leaks that allowed the plaintext recovery attacks.
Compared to OpenSSH 5.1, the updated version provides further command line options and minor functional enhancements. For example, the ssh -y option redirects logging to syslog and dynamic port forwarding was improved. The release changelog includes the list of fixed bugs.
OpenSSH emanates from the OpenBSD project, where a separate team focuses on OpenSSH's portability to different systems. The mirrors with the portable versions also include diffs against the OpenBSD source.
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
Plasma Bigscreen Returns
A developer discovered that the Plasma Bigscreen feature had been sitting untouched, so he decided to do something about it.
-
CachyOS Now Lets Users Choose Their Shell
Imagine getting the opportunity to select which shell you want during the installation of your favorite Linux distribution. That's now a thing.
-
Wayland 1.24 Released with Fixes and New Features
Wayland continues to move forward, while X11 slowly vanishes into the shadows, and the latest release includes plenty of improvements.
-
Bugs Found in sudo
Two critical flaws allow users to gain access to root privileges.
-
Fedora Continues 32-Bit Support
In a move that should come as a relief to some portions of the Linux community, Fedora will continue supporting 32-bit architecture.
-
Linux Kernel 6.17 Drops bcachefs
After a clash over some late fixes and disagreements between bcachefs's lead developer and Linus Torvalds, bachefs is out.
-
ONLYOFFICE v9 Embraces AI
Like nearly all office suites on the market (except LibreOffice), ONLYOFFICE has decided to go the AI route.
-
Two Local Privilege Escalation Flaws Discovered in Linux
Qualys researchers have discovered two local privilege escalation vulnerabilities that allow hackers to gain root privileges on major Linux distributions.
-
New TUXEDO InfinityBook Pro Powered by AMD Ryzen AI 300
The TUXEDO InfinityBook Pro 14 Gen10 offers serious power that is ready for your business, development, or entertainment needs.
-
LibreOffice Tested as Possible Office 365 Alternative
Another major organization has decided to test the possibility of migrating from Microsoft's Office 365 to LibreOffice.