Cisco IOS 12.2, 12.3, 12.4, 15.0, and 15.1, when the data-link switching (DLSw) feature is configured, allows remote attackers to cause a denial of service (device crash) by sending a sequence of malformed packets and leveraging a "narrow timing window," aka Bug ID CSCtf74999, a different vulnerability than CVE-2007-0199, CVE-2008-1152, and CVE-2009-0629.

The (1) Airline Product Set (aka ALPS), (2) Serial Tunnel Code (aka STUN), (3) Block Serial Tunnel Code (aka BSTUN), (4) Native Client Interface Architecture (NCIA) support, (5) Data-link switching (aka DLSw), (6) Remote Source-Route Bridging (RSRB), (7) Point to Point Tunneling Protocol (PPTP), (8) X.25 for Record Boundary Preservation (RBP), (9) X.25 over TCP (XOT), and (10) X.25 Routing features in Cisco IOS 12.2 and 12.4 allows remote attackers to cause a denial of service (device reload) via a series of crafted TCP packets.