CVE-2023-48795 (https://terrapin-attack.com/): The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the extension negotiation message), and a client and server may consequently end up with a connection for which some security features have been downgraded or disabled, aka a Terrapin attack. This occurs because the SSH Binary Packet Protocol (BPP), implemented by these extensions, mishandles the handshake phase and mishandles use of sequence numbers. For example, there is an effective attack against ChaCha20-Poly1305 (and CBC with Encrypt-then-MAC). The bypass occurs in chacha20-poly1305@openssh.com and (if CBC is used) the -etm@openssh.com MAC algorithms. This also affects Maverick Synergy Java SSH API before 3.1.0-SNAPSHOT, Dropbear through 2022.83, Ssh before 5.1.1 in Erlang/OTP, and PuTTY before 0.80; and there could be effects on Bitvise SSH through 9.31, AsyncSSH through 2.14.1, libssh through 0.10.5, and golang.org/x/crypto through 2023-12-17.
The bug has been referenced in the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=ca104be35e918af32f622d4f2e0850085e36da63 commit ca104be35e918af32f622d4f2e0850085e36da63 Author: Viorel Munteanu <ceamac@gentoo.org> AuthorDate: 2024-04-06 05:52:39 +0000 Commit: Viorel Munteanu <ceamac@gentoo.org> CommitDate: 2024-04-06 05:54:50 +0000 net-misc/dropbear: add 2024.84 Make the tests non-interactive just in case. Disable the tests that fail. Closes: https://bugs.gentoo.org/732294 Bug: https://bugs.gentoo.org/920293 Signed-off-by: Viorel Munteanu <ceamac@gentoo.org> net-misc/dropbear/Manifest | 2 + net-misc/dropbear/dropbear-2024.84.ebuild | 184 +++++++++++++++++++++ .../dropbear/files/dropbear-2024.84-dbscp.patch | 20 +++ .../dropbear-2024.84-non-interactive-tests.patch | 13 ++ 4 files changed, 219 insertions(+)
Here's the fix, in 2024.84 onwards: https://github.com/mkj/dropbear/commit/6e43be5c7b99dbee49dc72b6f989f29fdd7e9356
