CVE-2001-0751

Cisco CBOS < 2.3.8 - TCP Connection Spoofing via Predictable ISN

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2001-0751.

AI-analyzed exploit summary The vulnerability in the Linux kernel's 'secure_tcp_sequence_number' function allows remote users to predict TCP initial sequence numbers (ISNs) due to weak MD4-based generation. This can facilitate TCP session spoofing and bypass IP-based access controls.

Description

Cisco switches and routers running CBOS 2.3.8 and earlier use predictable TCP Initial Sequence Numbers (ISN), which allows remote attackers to spoof or hijack TCP connections.

Exploits (1)

exploitdb WRITEUP
remotelinux
https://www.exploit-db.com/exploits/19522

The vulnerability in the Linux kernel's 'secure_tcp_sequence_number' function allows remote users to predict TCP initial sequence numbers (ISNs) due to weak MD4-based generation. This can facilitate TCP session spoofing and bypass IP-based access controls.

Classification
Writeup 90%
Attack Type
Info Leak
Complexity
Moderate
Reliability
Theoretical
Target: Linux kernel (versions prior to fix)
No auth needed
Prerequisites: Network access to target system · Ability to observe or predict TCP sequence numbers
devstral-2 · analyzed Feb 19, 2026 Full analysis →

References (2)

Core 2
Core References
Patch, Vendor Advisory vendor-advisory x_refsource_cisco
http://www.cisco.com/warp/public/707/CBOS-multiple2-pub.html
Third Party Advisory, VDB Entry vdb-entry x_refsource_xf
https://exchange.xforce.ibmcloud.com/vulnerabilities/139

Scores

EPSS 0.0259
EPSS Percentile 83.3%

Details

Status published
Products (1)
cisco/cbos < 2.3.8
Published Oct 18, 2001
Tracked Since Feb 18, 2026