CVE-2006-5051: Signal handler race condition in OpenSSH before 4.4 allows remote attackers to cause a denial of service (crash), and possibly execute…
Noroxi assessment
Priority: Plan (action score 46/100)
- Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
- Probability of exploitation in the next 30 days: 45.5% (FIRST EPSS); higher than 98.8% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
- Fixed version: openssh (Debian:12) 1:4.6p1-1; openssh (Debian:3.1) 1:3.8.1p1-8.sarge.6; openssh-krb5 (Debian:3.1) 3.8.1p1-7sarge1.
Add it to your regular patch cycle. Upgrade to openssh (Debian:12) 1:4.6p1-1; openssh (Debian:3.1) 1:3.8.1p1-8.sarge.6; openssh-krb5 (Debian:3.1) 3.8.1p1-7sarge1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
Signal handler race condition in OpenSSH before 4.4 allows remote attackers to cause a denial of service (crash), and possibly execute arbitrary code if GSSAPI authentication is enabled, via unspecified vectors that lead to a double-free.
- Published
- Sep 27, 2006
- Updated
- Jun 16, 2026
- EPSS
- 45.5% · 98th percentile
- CWE
- CWE-415
Report tools
Action score
46
Add it to your regular patch cycle.
- CVSS
- 32 / 40 · 8.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 14 / 30 · 45.5%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- Proof of concept exists, no weaponized module
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is OpenSSH on your server exposed to the internet?Run a port scan
Is your version affected? Check itNoroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| openbsd | openssh | cpe:2.3:a:openbsd:openssh |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
| apple | mac os x | cpe:2.3:o:apple:mac_os_x |
| apple | mac os x server | cpe:2.3:o:apple:mac_os_x_server |
Is OpenSSH on your server exposed to the internet?
The free port scanner finds the open ports on your server and matches the service versions it can read against known vulnerabilities. No account needed.
Run a port scanAffected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- apple mac os xbefore 10.3.9
- apple mac os x10.4 and later · up to 10.4.8 inclusive
- apple mac os x serverbefore 10.3.9
- apple mac os x server10.4 and later · up to 10.4.8 inclusive
- debian debian linux3.1
- openbsd opensshup to 4.4 inclusive
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | openssh | before 1:4.6p1-1 | 1:4.6p1-1 |
| Debian:3.1 | openssh | before 1:3.8.1p1-8.sarge.6 | 1:3.8.1p1-8.sarge.6 |
| Debian:3.1 | openssh-krb5 | before 3.8.1p1-7sarge1 | 3.8.1p1-7sarge1 |
| Debian:4.0 | openssh | before 1:4.3p2-9etch3 | 1:4.3p2-9etch3 |
| Red Hat:enterprise_linux:2.1::as | openssh | before 0:3.1p1-21 | 0:3.1p1-21 |
| Red Hat:enterprise_linux:2.1::as | openssh-askpass | before 0:3.1p1-21 | 0:3.1p1-21 |
| Red Hat:enterprise_linux:2.1::as | openssh-askpass-gnome | before 0:3.1p1-21 | 0:3.1p1-21 |
| Red Hat:enterprise_linux:2.1::as | openssh-clients | before 0:3.1p1-21 | 0:3.1p1-21 |
| Red Hat:enterprise_linux:2.1::as | openssh-server | before 0:3.1p1-21 | 0:3.1p1-21 |
| Red Hat:enterprise_linux:3::as | openssh | before 0:3.6.1p2-33.30.12 | 0:3.6.1p2-33.30.12 |
| Red Hat:enterprise_linux:3::as | openssh-askpass | before 0:3.6.1p2-33.30.12 | 0:3.6.1p2-33.30.12 |
| Red Hat:enterprise_linux:3::as | openssh-askpass-gnome | before 0:3.6.1p2-33.30.12 | 0:3.6.1p2-33.30.12 |
| Red Hat:enterprise_linux:3::as | openssh-clients | before 0:3.6.1p2-33.30.12 | 0:3.6.1p2-33.30.12 |
| Red Hat:enterprise_linux:3::as | openssh-debuginfo | before 0:3.6.1p2-33.30.12 | 0:3.6.1p2-33.30.12 |
| Red Hat:enterprise_linux:3::as | openssh-server | before 0:3.6.1p2-33.30.12 | 0:3.6.1p2-33.30.12 |
| Red Hat:enterprise_linux:4::as | openssh | before 0:3.9p1-8.RHEL4.17 | 0:3.9p1-8.RHEL4.17 |
| Red Hat:enterprise_linux:4::as | openssh-askpass | before 0:3.9p1-8.RHEL4.17 | 0:3.9p1-8.RHEL4.17 |
| Red Hat:enterprise_linux:4::as | openssh-askpass-gnome | before 0:3.9p1-8.RHEL4.17 | 0:3.9p1-8.RHEL4.17 |
| Red Hat:enterprise_linux:4::as | openssh-clients | before 0:3.9p1-8.RHEL4.17 | 0:3.9p1-8.RHEL4.17 |
| Red Hat:enterprise_linux:4::as | openssh-debuginfo | before 0:3.9p1-8.RHEL4.17 | 0:3.9p1-8.RHEL4.17 |
| Red Hat:enterprise_linux:4::as | openssh-server | before 0:3.9p1-8.RHEL4.17 | 0:3.9p1-8.RHEL4.17 |
Same product
openbsd: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-123158sshd in OpenSSH before 10.6p2 on Linux, when musl libc is used without PAM, lacks a workaround for a password authentication bypass…KEV68This week
- CVE-2023-38408The PKCS#11 feature in ssh-agent in OpenSSH before 9.3p2 has an insufficiently trustworthy search path, leading to remote code execution if…63This week
- CVE-2018-15473OpenSSH through 7.7 is prone to a user enumeration vulnerability due to not delaying bailout for an invalid authenticating user until after…60This week
Published before and after this one in the same product
- ← EarlierCVE-2006-0225Jan 25, 2006 · scp in OpenSSH 4.2p1 allows attackers to execute arbitrary commands via filenames that contain shell metacharacters or spaces, which are…18Monitor
- ← EarlierCVE-2006-4924Sep 26, 2006 · sshd in OpenSSH before 4.4, when using the version 1 SSH protocol, allows remote attackers to cause a denial of service (CPU consumption)…42Plan
- Later →CVE-2006-5052Sep 27, 2006 · Unspecified vulnerability in portable OpenSSH before 4.4, when running on some platforms, allows remote attackers to determine the validity…21Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:openssh | 1:4.6p1-1 · Debian:12 | Package registry (OSV) |
| debian:openssh-krb5 | 3.8.1p1-7sarge1 · Debian:3.1 | Package registry (OSV) |
| red hat:openssh | 0:3.6.1p2-33.30.12 · Red Hat:enterprise_linux:3::as | Package registry (OSV) |
| red hat:openssh-askpass | 0:3.6.1p2-33.30.12 · Red Hat:enterprise_linux:3::as | Package registry (OSV) |
| red hat:openssh-askpass-gnome | 0:3.6.1p2-33.30.12 · Red Hat:enterprise_linux:3::as | Package registry (OSV) |
| red hat:openssh-clients | 0:3.6.1p2-33.30.12 · Red Hat:enterprise_linux:3::as | Package registry (OSV) |
| red hat:openssh-debuginfo | 0:3.6.1p2-33.30.12 · Red Hat:enterprise_linux:3::as | Package registry (OSV) |
| red hat:openssh-server | 0:3.6.1p2-33.30.12 · Red Hat:enterprise_linux:3::as | Package registry (OSV) |
Exploit status
Proof of concept available
A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.
Evidence
- Proof-of-concept repository on GitHub ×3
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Proof-of-concept repository on GitHub | 3 repositories | 2024-07-01 → 2024-10-22 |
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Published
- First PoC+6486 d
- TodayNov 14, 2026+7352 d
Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-415 · Double FreeCVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log (1)
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (19 more)Show less
- ftp://patches.sgi.com/support/free/security/advisories/20061001-01-P.asc
- docs.info.apple.com/article.html?artnum=305214
- lists.apple.com/archives/security-announce/2007/Mar/msg00002.html
- lists.freebsd.org/pipermail/freebsd-security/2006-October/004051.html
- marc.info/?l=openssh-unix-dev&m=115939141729160&w=2
- openssh.org/txt/release-4.4
- secunia.com/advisories/22158
- secunia.com/advisories/22173
- secunia.com/advisories/22183
- secunia.com/advisories/22196
- secunia.com/advisories/22208
- secunia.com/advisories/22236
- secunia.com/advisories/22245
- secunia.com/advisories/22270
- secunia.com/advisories/22352
- secunia.com/advisories/22362
- secunia.com/advisories/22487
- secunia.com/advisories/22495
- secunia.com/advisories/22823
Vendor advisories and official records. Exploit/PoC links are deliberately left out.