CVE-2003-0209Snort Vulnerability
Integer overflow in the TCP stream reassembly module (stream4) for Snort 2.0 and earlier allows remote attackers to execute arbitrary code via large sequence numbers in packets, which enable a heap-based buffer overflow.
Published May 5, 2003 · Updated Apr 15, 2026
Key Facts
Patch immediately- CVE-2003-0209 is a critical-severity vulnerability (CVSS 10.0 v2) affecting Smoothwall, Snort (Sourcefire).
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 39% probability of exploitation in the next 30 days.
- Fixed versions are available, including Snort 1.8.4beta1-3.1.
- Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
Scores
CVSS v2
10.0
AV:N/AC:L/Au:N/C:C/I:C/A:C
EPSS (30-day exploit likelihood)
39%
Higher than 98.5% of all scored CVEs
Exploit maturity
Proof of concept
ATLAS score
40/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Not listed
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
Proof of concept
Public exploit code
1
Proof-of-concept links
In-the-wild evidence
0
Reports of active use
Description
Integer overflow in the TCP stream reassembly module (stream4) for Snort 2.0 and earlier allows remote attackers to execute arbitrary code via large sequence numbers in packets, which enable a heap-based buffer overflow.
Affected Products
12 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| SmoothwallSmoothwall | 2.0_beta_4 | n/a |
| SnortSourcefire | 1.8, 1.8.1, 1.8.2, 1.8.3, 1.8.4, 1.8.5, 1.8.6, 1.8.7 | 1.8.4beta1-3.1 |
Patched Releases
Snort
1.8.4beta1-3.1
Timeline
Publicly disclosed
May 5, 2003
Last updated
Apr 15, 2026
References
- advisoryVU#139129
- patch7178
- exploitExploitDB-18
- other20030415 CORE-2003-0307: Snort TCP Stream Reassembly Integer Overflow Vulnerability
- other20030422 GLSA: snort (200304-05)
FAQ
Common Questions.
Integer overflow in the TCP stream reassembly module (stream4) for Snort 2.0 and earlier allows remote attackers to execute arbitrary code via large sequence numbers in packets, which enable a heap-based buffer overflow.
Affected: Smoothwall versions 2.0_beta_4; Snort (Sourcefire) versions 1.8, 1.8.1, 1.8.2, 1.8.3, 1.8.4, 1.8.5, 1.8.6, 1.8.7. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including Snort 1.8.4beta1-3.1.
Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
Is CVE-2003-0209 On Your Attack Surface?
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