Описание
A flaw was found in libssh. A remote attacker, by controlling client configuration files or known_hosts files, could craft specific hostnames that when processed by the match_pattern() function can lead to inefficient regular expression backtracking. This can cause timeouts and resource exhaustion, resulting in a Denial of Service (DoS) for the client.
Отчет
The vulnerability in libssh has been rated as Low by Red Hat Product Security. This issue arises from inefficient pattern matching logic that may lead to excessive processing time when handling specially crafted patterns. However, these patterns originate from configuration data, meaning an attacker would need the ability to modify or influence configuration files to exploit the issue. As a result, exploitation requires local access or equivalent local privileges, and cannot be performed remotely without prior compromise. Additionally, triggering the issue depends on specific conditions during pattern evaluation, increasing the attack complexity. The impact of this flaw is limited to potential performance degradation or temporary delays due to increased CPU usage. It does not allow unauthorized access to data, modification of system state, or execution of arbitrary code.
Меры по смягчению последствий
Avoid using complex patterns in configuration files and known_hosts.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 6 | libssh2 | Not affected | ||
| Red Hat Enterprise Linux 7 | libssh2 | Not affected | ||
| Red Hat Enterprise Linux 8 | libssh | Fix deferred | ||
| Red Hat Hardened Images | libssh2 | Not affected | ||
| Red Hat OpenShift Container Platform 4 | rhcos | Fix deferred | ||
| Red Hat Enterprise Linux 10 | libssh | Fixed | RHSA-2026:18160 | 19.05.2026 |
| Red Hat Enterprise Linux 9 | libssh | Fixed | RHSA-2026:18683 | 19.05.2026 |
| Red Hat Enterprise Linux 9 | libssh | Fixed | RHSA-2026:18683 | 19.05.2026 |
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Дополнительная информация
Статус:
EPSS
2.2 Low
CVSS3
Связанные уязвимости
A flaw was found in libssh. A remote attacker, by controlling client configuration files or known_hosts files, could craft specific hostnames that when processed by the `match_pattern()` function can lead to inefficient regular expression backtracking. This can cause timeouts and resource exhaustion, resulting in a Denial of Service (DoS) for the client.
A flaw was found in libssh. A remote attacker, by controlling client configuration files or known_hosts files, could craft specific hostnames that when processed by the `match_pattern()` function can lead to inefficient regular expression backtracking. This can cause timeouts and resource exhaustion, resulting in a Denial of Service (DoS) for the client.
Libssh: libssh: denial of service via inefficient regular expression processing
A flaw was found in libssh. A remote attacker, by controlling client c ...
A flaw was found in libssh. A remote attacker, by controlling client configuration files or known_hosts files, could craft specific hostnames that when processed by the `match_pattern()` function can lead to inefficient regular expression backtracking. This can cause timeouts and resource exhaustion, resulting in a Denial of Service (DoS) for the client.
EPSS
2.2 Low
CVSS3