CVE-2006-4924Openssh Vulnerability
sshd in OpenSSH before 4.4, when using the version 1 SSH protocol, allows remote attackers to cause a denial of service (CPU consumption) via an SSH packet that contains duplicate blocks, which is not properly handled by the CRC compensation attack detector.
Published Sep 27, 2006 · Updated Aug 4, 2026 · Also known as DEBIAN-CVE-2006-4924, DSA-1189-1, DSA-1212, DSA-1212-1
Key Facts
Patch immediately- CVE-2006-4924 is a high-severity vulnerability (CVSS 7.8 v2) affecting Openssh (Openbsd), openssh-krb5 (debian), rootio-openssh.
- It is not listed in any known-exploited vulnerabilities catalog. A public exploit is reported by tracking sources, but no code link is listed yet.
- EPSS estimates a 38% probability of exploitation in the next 30 days.
- Fixed versions are available, including Openssh 0:3.1p1-21, Openssh 1:3.8.1p1-8.sarge.6, Openssh 1:4.3p2-4.
- Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
Scores
CVSS v2
7.8
AV:N/AC:L/Au:N/C:N/I:N/A:C
EPSS (30-day exploit likelihood)
38%
Higher than 98.5% of all scored CVEs
Exploit maturity
Proof of concept
ATLAS score
43/100
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
Advisories And Exploit References
- advisoryhttps://security-tracker.debian.org/tracker/CVE-2006-4924
- advisoryRHSA-2006:0697
- advisoryRHSA-2006:0698
- advisory21923
- advisory22091
- advisory22116
Description
sshd in OpenSSH before 4.4, when using the version 1 SSH protocol, allows remote attackers to cause a denial of service (CPU consumption) via an SSH packet that contains duplicate blocks, which is not properly handled by the CRC compensation attack detector.
Affected Products
72 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| OpensshOpenbsd | 1.2, 1.2.1, 1.2.2, 1.2.27, 1.2.3, 2.1, 2.1.1, 2.2 | 1:4.3p2-4 |
| openssh-krb5debian | See advisory | 3.8.1p1-7sarge1 |
| rootio-opensshrootio | See advisory | 1:4.3p2-4 |
Patched Releases
Openssh
0:3.1p1-21, 1:3.8.1p1-8.sarge.6, 1:4.3p2-4
openssh-krb5
3.8.1p1-7sarge1
rootio-openssh
1:4.3p2-4
Timeline
Publicly disclosed
Sep 27, 2006
Last updated
Aug 4, 2026
Weakness Type
- CWE-399
References
- advisorysecurity-tracker.debian.org · CVE-2006-4924
- advisoryRHSA-2006:0697
- advisoryRHSA-2006:0698
- advisory21923
- advisory22091
FAQ
Common Questions.
sshd in OpenSSH before 4.4, when using the version 1 SSH protocol, allows remote attackers to cause a denial of service (CPU consumption) via an SSH packet that contains duplicate blocks, which is not properly handled by the CRC compensation attack detector.
Affected: Openssh (Openbsd) versions 1.2, 1.2.1, 1.2.2, 1.2.27, 1.2.3, 2.1, 2.1.1, 2.2; openssh-krb5 (debian); 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.
A public exploit is reported by tracking sources, but no code link is listed yet.
Fixed versions are available, including Openssh 0:3.1p1-21, Openssh 1:3.8.1p1-8.sarge.6, Openssh 1:4.3p2-4.
Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
Is CVE-2006-4924 On Your Attack Surface?
Brandefense matches it against the products discovered on your perimeter and opens a finding the day a CVE like this is listed.
Request A Demo