Headline
Debian Security Advisory 5599-1
Debian Linux Security Advisory 5599-1 - Fabian Baeumer, Marcus Brinkmann and Joerg Schwenk discovered that the SSH protocol is prone to a prefix truncation attack, known as the "Terrapin attack". This attack allows a MITM attacker to effect a limited break of the integrity of the early encrypted SSH transport protocol by sending extra messages prior to the commencement of encryption, and deleting an equal number of consecutive messages immediately after encryption starts.
-----BEGIN PGP SIGNED MESSAGE-----Hash: SHA512- -------------------------------------------------------------------------Debian Security Advisory DSA-5599-1 [email protected]://www.debian.org/security/ Sebastien DelafondJanuary 12, 2024 https://www.debian.org/security/faq- -------------------------------------------------------------------------Package : phpseclibCVE ID : CVE-2023-48795Fabian Baeumer, Marcus Brinkmann and Joerg Schwenk discovered that theSSH protocol is prone to a prefix truncation attack, known as the"Terrapin attack". This attack allows a MITM attacker to effect alimited break of the integrity of the early encrypted SSH transportprotocol by sending extra messages prior to the commencement ofencryption, and deleting an equal number of consecutive messagesimmediately after encryption starts.Details can be found at https://terrapin-attack.com/For the oldstable distribution (bullseye), this problem has been fixedin version 1.0.19-3+deb11u1.For the stable distribution (bookworm), this problem has been fixed inversion 1.0.20-1+deb12u1.We recommend that you upgrade your phpseclib packages.For the detailed security status of phpseclib please refer toits security tracker page at:https://security-tracker.debian.org/tracker/phpseclibFurther information about Debian Security Advisories, how to applythese updates to your system and frequently asked questions can befound at: https://www.debian.org/security/Mailing list: [email protected] PGP SIGNATURE-----iQEzBAEBCgAdFiEEAqSkbVtrXP4xJMh3EL6Jg/PVnWQFAmWg5PMACgkQEL6Jg/PVnWS6iwgAgCFsThzoeNHG05PouaajhL6LvGsrj+cwed14VEnr0TGpChD6y2Z/deZXHW86VXSHRZvqNTt7+UQvKUwrmvbNRZL3TQoTp9l+VKtn3wT/0Q6Zf1jsn4G+yffXdredHf2pXgJh9poEy2DUTunVF+vpZdp9fS2QY8xp24kNbk8kk6itJeOGueWoFwrZp1B5q2hnQdFtM8mhbXDzViqbiu6zVZOmSXri1jShAKRDl0kpRQvfP1mKE+j5RMoJkBGFGuWnIXvxtwQEYDvobgKk5Ie0yzwqnD6m3WXMeS9x4Zi+HvV3hXvEu0UvvQXC1z8VX31cFffkLLDFpO3cE9dQlyABBA==Rz3N-----END PGP SIGNATURE-----
Related news
Red Hat Security Advisory 2024-8235-03 - Red Hat OpenShift Container Platform release 4.14.39 is now available with updates to packages and images that fix several bugs and add enhancements. Issues addressed include code execution, denial of service, and out of bounds write vulnerabilities.
Debian Linux Security Advisory 5750-1 - Support for the "strict kex" SSH extension has been backported to AsyncSSH (a Python implementation of the SSHv2 protocol) as hardening against the Terrapin attack.
Red Hat Security Advisory 2024-4329-03 - Red Hat OpenShift Container Platform release 4.14.32 is now available with updates to packages and images that fix several bugs and add enhancements. Issues addressed include a bypass vulnerability.
Red Hat Security Advisory 2024-0041-03 - Red Hat OpenShift Container Platform release 4.16.0 is now available with updates to packages and images that fix several bugs and add enhancements. Issues addressed include denial of service, memory exhaustion, password leak, and resource exhaustion vulnerabilities.
Red Hat Security Advisory 2024-3479-03 - Updated container images are now available for director Operator for Red Hat OpenStack Platform 16.2 for RHEL 8.4. Issues addressed include a denial of service vulnerability.
Red Hat Security Advisory 2024-1859-03 - OpenShift API for Data Protection 1.3.1 is now available. Issues addressed include a denial of service vulnerability.
Red Hat Security Advisory 2024-1557-03 - An update is now available for Red Hat OpenShift Builds 1.0. Issues addressed include denial of service and traversal vulnerabilities.
Red Hat Security Advisory 2024-1197-03 - A security update is now available for Red Hat JBoss Enterprise Application Platform 7.4.
Red Hat Security Advisory 2024-1192-03 - An update is now available for Red Hat JBoss Enterprise Application Platform 8.0 for Red Hat Enterprise Linux 8. Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link in the References section. Issues addressed include denial of service and file overwrite vulnerabilities.
Red Hat Security Advisory 2024-1150-03 - An update for buildah is now available for Red Hat Enterprise Linux 9.
Red Hat Security Advisory 2024-0954-03 - The components for Red Hat OpenShift for Windows Containers 10.15.0 are now available. This product release includes bug fixes and security updates for the following packages: windows-machine-config-operator and windows-machine-config-operator-bundle. Issues addressed include a privilege escalation vulnerability.
Red Hat Security Advisory 2024-0843-03 - Red Hat OpenShift Serverless version 1.31.1 is now available. Issues addressed include denial of service and traversal vulnerabilities.
Red Hat Security Advisory 2024-0789-03 - An update for Red Hat Build of Apache Camel 4.0 for Quarkus 3.2 is now available. Issues addressed include buffer overflow and denial of service vulnerabilities.
Red Hat Security Advisory 2024-0628-03 - An update for libssh is now available for Red Hat Enterprise Linux 8.
Ubuntu Security Notice 6598-1 - Fabian Bäumer, Marcus Brinkmann, Joerg 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.
Ubuntu Security Notice 6585-1 - Fabian Bäumer, Marcus Brinkmann, Joerg 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.
Debian Linux Security Advisory 5601-1 - Fabian Baeumer, Marcus Brinkmann and Joerg Schwenk discovered that the SSH protocol is prone to a prefix truncation attack, known as the "Terrapin attack". This attack allows a MITM attacker to effect a limited break of the integrity of the early encrypted SSH transport protocol by sending extra messages prior to the commencement of encryption, and deleting an equal number of consecutive messages immediately after encryption starts.
Debian Linux Security Advisory 5600-1 - Fabian Baeumer, Marcus Brinkmann and Joerg Schwenk discovered that the SSH protocol is prone to a prefix truncation attack, known as the "Terrapin attack". This attack allows a MITM attacker to effect a limited break of the integrity of the early encrypted SSH transport protocol by sending extra messages prior to the commencement of encryption, and deleting an equal number of consecutive messages immediately after encryption starts.
Security researchers from Ruhr University Bochum have discovered a vulnerability in the Secure Shell (SSH) cryptographic network protocol that could allow an attacker to downgrade the connection's security by breaking the integrity of the secure channel. Called Terrapin (CVE-2023-48795, CVSS score: 5.9), the exploit has been described as the "first ever practically exploitable prefix
Debian Linux Security Advisory 5591-1 - Several vulnerabilities were discovered in libssh, a tiny C SSH library.
Gentoo Linux Security Advisory 202312-16 - Multiple vulnerabilities have been discovered in libssh, the worst of which could lead to code execution. Versions greater than or equal to 0.10.6 are affected.
Gentoo Linux Security Advisory 202312-17 - Multiple vulnerabilities have been discovered in OpenSSH, the worst of which could lead to code execution. Versions greater than or equal to 9.6_p1 are affected.
Debian Linux Security Advisory 5586-1 - Several vulnerabilities have been discovered in OpenSSH, an implementation of the SSH protocol suite.
Ubuntu Security Notice 6561-1 - Fabian Bäumer, Marcus Brinkmann, Joerg 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.
Ubuntu Security Notice 6560-1 - Fabian Bäumer, Marcus Brinkmann, Joerg 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. Luci Stanescu discovered that OpenSSH incorrectly added destination constraints when smartcard keys were added to ssh-agent, contrary to expectations. This issue only affected Ubuntu 22.04 LTS, and Ubuntu 23.04.
### Summary Russh v0.40.1 and earlier is vulnerable to a novel prefix truncation attack (a.k.a. Terrapin attack), which allows a man-in-the-middle attacker to strip an arbitrary number of messages right after the initial key exchange, breaking SSH extension negotiation (RFC8308) in the process and thus downgrading connection security. ### Mitigations To mitigate this protocol vulnerability, OpenSSH suggested a so-called "strict kex" which alters the SSH handshake to ensure a Man-in-the-Middle attacker cannot introduce unauthenticated messages as well as convey sequence number manipulation across handshakes. Support for strict key exchange has been added to Russh in the patched version. **Warning: To take effect, both the client and server must support this countermeasure.** As a stop-gap measure, peers may also (temporarily) disable the affected algorithms and use unaffected alternatives like AES-GCM instead until patches are available. ### Details The SSH specifications of Ch...