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.
CVE-2001-0288
This CVE was only ever scored under CVSS v2.0. NVD CVSS v2.0 base 7.5 — v2 rates that HIGH (v2 bands: LOW 0.0–3.9 / MEDIUM 4.0–6.9 / HIGH 7.0–10.0; v2 has no CRITICAL band). Vector AV:N/AC:L/Au:N/C:P/I:P/A:P. CVSS v2 is an older, coarser metric than v3.1/v4.0 (no Scope, no User Interaction, no Attack Requirements), so it is not directly comparable to a v3 or v4 score. NVD has never re-scored this record under v3. EPSS predicts 5.4% exploitation probability in the next 30 days, which is reflected in EG Risk but does not lift the v2 base. Confidence: LOW.
- Public exploit code is available (Exploit-DB (verified), public exploit)
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v2.0 (legacy)
- 7.5HIGHNVD never assigned a CVSS v3 rating to this CVE
- EG Score
- 7.5(low)
- EG Risk
- 64(Track)EG Risk 64/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation65% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 5%
- EPSS %ILE
- 92%
- KEV
- Not listed
Published
May 3, 2001
Last Modified
June 16, 2026
References (2)
- cve@mitrehttp://www.cisco.com/warp/public/707/ios-tcp-isn-random-pub.shtml
- af854a3a-2127-422b-91ae-364da2661108http://www.cisco.com/warp/public/707/ios-tcp-isn-random-pub.shtml
Data Freshness Timeline
(refreshed 6× in last 7d / 16× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-26 13:21 UTCEG score recompute▲ 7.50
- 2026-07-23 00:42 UTCEG score recompute
- 2026-07-23 00:25 UTCEG score recompute
- 2026-07-22 23:47 UTCEG score recompute
- 2026-07-22 21:27 UTCEG score recompute
- 2026-07-20 17:02 UTCEPSS rescore
- 2026-07-18 09:59 UTCEPSS rescore
- 2026-07-16 16:58 UTCEPSS rescore
- 2026-07-15 16:53 UTCEPSS rescore
- 2026-07-15 01:55 UTCEPSS rescore
- 2026-07-11 08:22 UTCEPSS rescore
- 2026-07-08 15:08 UTCEPSS rescore
- 2026-07-04 06:26 UTCEPSS rescore
- 2026-07-02 14:00 UTCEPSS rescore
- 2026-06-29 14:02 UTCEPSS rescore
- 2026-06-28 14:02 UTCEPSS rescore
- 2026-06-27 03:04 UTCEPSS rescore
- 2026-06-24 14:01 UTCEPSS rescore
- 2026-06-23 21:29 UTCEPSS rescore
- 2026-06-22 14:22 UTCEPSS rescore
- 2026-06-21 01:56 UTCEPSS rescore
- 2026-06-19 19:22 UTCEPSS rescore
- 2026-06-18 17:49 UTCEPSS rescore
- 2026-06-18 17:49 UTCEPSS rescore
- 2026-06-17 17:49 UTCEPSS rescore
Show 39 moreShow fewer
- 2026-06-16 17:49 UTCEPSS rescore
- 2026-06-14 23:13 UTCEPSS rescore
- 2026-06-13 22:56 UTCEPSS rescore
- 2026-06-12 23:07 UTCEPSS rescore
- 2026-06-11 13:55 UTCEPSS rescore
- 2026-06-10 22:13 UTCEPSS rescore
- 2026-06-10 13:17 UTCEPSS rescore
- 2026-06-08 14:13 UTCEPSS rescore
- 2026-06-07 15:21 UTCEPSS rescore
- 2026-06-06 13:44 UTCEPSS rescore
- 2026-06-05 06:07 UTCEPSS rescore
- 2026-06-04 13:09 UTCEPSS rescore
- 2026-06-02 20:10 UTCEPSS rescore
- 2026-06-01 13:48 UTCEPSS rescore
- 2026-05-31 22:27 UTCEPSS rescore
- 2026-05-31 20:47 UTCEG score recompute
- 2026-05-31 20:47 UTCGHSA enrichment
- 2026-05-31 00:13 UTCEPSS rescore
- 2026-05-31 00:13 UTCEPSS rescore
- 2026-05-29 13:40 UTCEPSS rescore
- 2026-05-28 13:42 UTCEPSS rescore
- 2026-05-28 13:42 UTCEPSS rescore
- 2026-05-28 13:42 UTCEPSS rescore
- 2026-05-28 13:42 UTCEPSS rescore
- 2026-05-27 13:37 UTCEPSS rescore
- 2026-05-27 13:37 UTCEPSS rescore
- 2026-05-26 13:41 UTCEPSS rescore
- 2026-05-26 13:41 UTCEPSS rescore
- 2026-05-26 13:41 UTCEPSS rescore
- 2026-05-26 07:16 UTCEPSS rescore
- 2026-05-26 07:16 UTCEPSS rescore
- 2026-05-24 16:42 UTCEPSS rescore
- 2026-05-22 21:15 UTCEPSS rescore
- 2026-05-21 22:38 UTCEPSS rescore
- 2026-05-20 22:36 UTCEPSS rescore
- 2026-05-20 11:20 UTCEPSS rescore
- 2026-05-20 11:20 UTCEPSS rescore
- 2026-05-18 21:29 UTCEPSS rescore
- 2026-05-18 21:29 UTCEPSS rescore
Publicly available exploits
(1 reference)Working exploit code is in the public domain (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.
- Exploit-DBEDB-19522✓ verifiedFirst seen Sep 27, 1999
Linux Kernel 2.2 - Predictable TCP Initial Sequence Number
Open source ↗
Frequently asked(4)
What is CVE-2001-0288?
When was CVE-2001-0288 disclosed?
Is CVE-2001-0288 actively exploited?
How do I remediate CVE-2001-0288?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2001-0288
Is Your Infrastructure Affected by CVE-2001-0288?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.