Описание
The resend_bytes function in roaming_common.c in the client in OpenSSH 5.x, 6.x, and 7.x before 7.1p2 allows remote servers to obtain sensitive information from process memory by requesting transmission of an entire buffer, as demonstrated by reading a private key.
An information leak flaw was found in the way the OpenSSH client roaming feature was implemented. A malicious server could potentially use this flaw to leak portions of memory (possibly including private SSH keys) of a successfully authenticated OpenSSH client.
Отчет
This issue does not affect the version OpenSSH as shipped with Red Hat Enterprise Linux 4, 5 and 6. This issue affects the version of OpenSSH as shipped with Red Hat Enterprise Linux 7 in a non-default configuration. For more information please refer to https://access.redhat.com/articles/2123781
Меры по смягчению последствий
- The vulnerable roaming code can be permanently disabled by adding the undocumented option "UseRoaming no" to the system-wide configuration file (usually /etc/ssh/ssh_config), or per-user configuration file (~/.ssh/config), or command-line (-o "UseRoaming no").
- If an OpenSSH client is disconnected from an SSH server that offers roaming, it prints "[connection suspended, press return to resume]" on stderr, and waits for '\n' or '\r' on stdin (and not on the controlling terminal) before it reconnects to the server; advanced users may become suspicious and press Control-C or Control-Z instead, thus avoiding the information leak. However, SSH commands that use the local stdin to transfer data to the remote server are bound to trigger this reconnection automatically (upon reading a '\n' or '\r' from stdin). Moreover, these non-interactive SSH commands (for example, backup scripts and cron jobs) commonly employ public-key authentication and are therefore perfect targets for this information leak.
Затронутые пакеты
Платформа | Пакет | Состояние | Рекомендация | Релиз |
---|---|---|---|---|
Red Hat Enterprise Linux 4 | openssh | Not affected | ||
Red Hat Enterprise Linux 5 | openssh | Not affected | ||
Red Hat Enterprise Linux 6 | openssh | Not affected | ||
Red Hat Enterprise Linux 7 | openssh | Fixed | RHSA-2016:0043 | 14.01.2016 |
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Дополнительная информация
Статус:
EPSS
4.3 Medium
CVSS2
Связанные уязвимости
The resend_bytes function in roaming_common.c in the client in OpenSSH 5.x, 6.x, and 7.x before 7.1p2 allows remote servers to obtain sensitive information from process memory by requesting transmission of an entire buffer, as demonstrated by reading a private key.
The resend_bytes function in roaming_common.c in the client in OpenSSH 5.x, 6.x, and 7.x before 7.1p2 allows remote servers to obtain sensitive information from process memory by requesting transmission of an entire buffer, as demonstrated by reading a private key.
The resend_bytes function in roaming_common.c in the client in OpenSSH ...
The resend_bytes function in roaming_common.c in the client in OpenSSH 5.x, 6.x, and 7.x before 7.1p2 allows remote servers to obtain sensitive information from process memory by requesting transmission of an entire buffer, as demonstrated by reading a private key.
Уязвимость функции resend_bytes средства криптографической защиты OpenSSH, позволяющая нарушителю получить несанкционированный доступ к защищаемой информации
EPSS
4.3 Medium
CVSS2