SB2015073006 - Permissions, Privileges, and Access Controls in openssh (Alpine package)
Published: July 30, 2015
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2015-5600)
The vulnerability allows a remote non-authenticated attacker to #BASIC_IMPACT#.
The kbdint_next_device function in auth2-chall.c in sshd in OpenSSH through 6.9 does not properly restrict the processing of keyboard-interactive devices within a single connection, which makes it easier for remote attackers to conduct brute-force attacks or cause a denial of service (CPU consumption) via a long and duplicative list in the ssh -oKbdInteractiveDevices option, as demonstrated by a modified client that provides a different password for each pam element on this list.
Remediation
Install update from vendor's website.
References
- https://git.alpinelinux.org/aports/commit/?id=8a07923212fef85b959a7a5d33641b887bb28926
- https://git.alpinelinux.org/aports/commit/?id=3885568b0e267af8bd7ce20f4c0337c84312da01
- https://git.alpinelinux.org/aports/commit/?id=349ad37b3400ed4f7f3fb02db6fec33d252dd704
- https://git.alpinelinux.org/aports/commit/?id=4c781145fea2f72a16dcf5acd51e426850ef540a
- https://git.alpinelinux.org/aports/commit/?id=f313c8ea055322f60121a3baf75c0d16ea154978