CVE-2002-0640Openssh Vulnerability
Buffer overflow in sshd in OpenSSH 2.3.1 through 3.3 may allow remote attackers to execute arbitrary code via a large number of responses during challenge response authentication when OpenBSD is using PAM modules with interactive keyboard authentication…
Published Jul 3, 2002 · Updated Aug 4, 2026 · Also known as DEBIAN-CVE-2002-0640
Key Facts
Patch immediately- CVE-2002-0640 is a critical-severity vulnerability (CVSS 10.0 v2) affecting Openssh (Openbsd), rootio-openssh.
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 27% probability of exploitation in the next 30 days.
- Fixed versions are available, including Openssh 1:3.4, rootio-openssh 1:3.4.
- 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)
27%
Higher than 98.0% of all scored CVEs
Exploit maturity
Proof of concept
ATLAS score
46/100
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
2
Proof-of-concept links
In-the-wild evidence
0
Reports of active use
Advisories And Exploit References
- advisoryhttps://security-tracker.debian.org/tracker/CVE-2002-0640
- advisoryRHSA-2002:127
- advisoryRHSA-2002:131
Description
Buffer overflow in sshd in OpenSSH 2.3.1 through 3.3 may allow remote attackers to execute arbitrary code via a large number of responses during challenge response authentication when OpenBSD is using PAM modules with interactive keyboard authentication (PAMAuthenticationViaKbdInt).
Affected Products
40 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| OpensshOpenbsd | 1.2.2, 1.2.3, 2.1, 2.1.1, 2.2, 2.3, 2.5, 2.5.1 | 1:3.4 |
| rootio-opensshrootio | See advisory | 1:3.4 |
Patched Releases
Openssh
1:3.4
rootio-openssh
1:3.4
Timeline
Publicly disclosed
Jul 3, 2002
Last updated
Aug 4, 2026
References
- advisorysecurity-tracker.debian.org · CVE-2002-0640
- advisoryRHSA-2002:127
- advisoryRHSA-2002:131
- exploitExploitDB-21578
- exploitExploitDB-21579
FAQ
Common Questions.
Buffer overflow in sshd in OpenSSH 2.3.1 through 3.3 may allow remote attackers to execute arbitrary code via a large number of responses during challenge response authentication when OpenBSD is using PAM modules with interactive keyboard authentication (PAMAuthenticationViaKbdInt).
Affected: Openssh (Openbsd) versions 1.2.2, 1.2.3, 2.1, 2.1.1, 2.2, 2.3, 2.5, 2.5.1; rootio-openssh. 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 Openssh 1:3.4, rootio-openssh 1:3.4.
Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
Is CVE-2002-0640 On Your Attack Surface?
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