FreeBSD AES-XCBC-MAC algorithm security bypass
| freebsd-aesxcbcmac-security-bypass (21551) |  High Risk |
Description:
FreeBSD could allow a remote attacker to bypass security restrictions caused by a programming error in the implementation of the AES-XCBC-MAC algorithm used for authentication. If the AES-XCBC-MAC algorithm is used without any encryption, a remote attacker could forge packets to appear as if the packets orginated from a different system to establish an IPsec session. This would allow the attacker to gain unauthorized access to sensitive information or possibly gain elevated privileges on the system.
Consequences:
Bypass Security
Remedy:
For FreeBSD:
Upgrade to the latest version of FreeBSD (5-STABLE or to RELENG_5_4, RELENG_5_3 security branch dated later than 2005-07-27), as listed in FreeBSD Security Advisory FreeBSD-SA-05:19. See References.
— OR —
Apply the appropriate patch for your system, as listed in the FreeBSD Security Advisory FreeBSD-SA-05:19. See References.
References:
- FreeBSD Security Advisory FreeBSD-SA-05:19.ipsec: Incorrect key usage in AES-XCBC-MAC.
- BID-14394: BSD IPsec Session AES-XCBC-MAC Authentication Constant Key Usage Vulnerability
- CVE-2005-2359: The AES-XCBC-MAC algorithm in IPsec in FreeBSD 5.3 and 5.4, when used for authentication without other encryption, uses a constant key instead of the one that was assigned by the system administrator, which can allow remote attackers to spoof packets to establish an IPsec session.
- SA16244: FreeBSD IPsec AES-XCBC-MAC Authentication Security Issue
- SECTRACK ID: 1014586: FreeBSD Bug in IPSec AES-XCBC-MAC Algorithm May Cause the Incorrect Key to Be Used
Platforms Affected:
- FreeBSD FreeBSD 5.3
- FreeBSD FreeBSD 5.4
Reported:
Jul 27, 2005
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For corrections or additions please email xforce@iss.net