CVE-2001-0288

Severity: high (CVSS 7.5 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 5.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2001-05-03 · updated 2026-06-16

Description

Cisco switches and routers running IOS 12.1 and earlier produce predictable TCP Initial Sequence Numbers (ISNs), which allows remote attackers to spoof or hijack TCP connections.

Affected products

Cisco IOS: through 12.1

References

http://www.cisco.com/warp/public/707/ios-tcp-isn-random-pub.shtml
http://www.cisco.com/warp/public/707/ios-tcp-isn-random-pub.shtml

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