Sysax Multi-Server <= 6.10 SSHD Key Exchange DoS
Published Aug 5, 2025
8.7
HIGHCVSS 4.0
EPSS 1.64%
Description
A denial-of-service vulnerability exists in Sysax Multi-Server version 6.10 via its SSH daemon. A specially crafted SSH key exchange packet can trigger a crash in the service, resulting in loss of availability. The flaw is triggered during the handling of malformed key exchange data, including a non-standard byte (\x28) in place of the expected SSH protocol delimiter.
Affected products
-
- Version 6.10StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Sysax Software | Multi-Server | n/a |
|
- 6.10
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
1 other source (NVD) ▾
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
PoCAutomatable
YesTechnical Impact
PartialDecision
n/aAssessed Aug 7, 2025 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2025–2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (9 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 1.64% (0.01636) | 75.45th | v5 (v2026.06.15) |
| Jun 15, 2026 | 1.09% (0.01094) | 61.08th | v5 (v2026.06.15) |
| Jun 13, 2026 | 73.61% (0.73615) | 98.83th | v4 (v2025.03.14) |
| Jun 1, 2026 | 71.07% (0.71068) | 98.73th | v4 (v2025.03.14) |
| Apr 21, 2026 | 53.06% (0.53061) | 97.97th | v4 (v2025.03.14) |
| Jan 1, 2026 | 49.75% (0.49751) | 97.72th | v4 (v2025.03.14) |
| Dec 5, 2025 | 61.16% (0.61161) | 98.21th | v4 (v2025.03.14) |
| Oct 8, 2025 | 55.24% (0.55244) | 97.93th | v4 (v2025.03.14) |
| Aug 6, 2025 | 0.04% (0.00042) | 11.86th | v4 (v2025.03.14) |
References (4)
- https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/auxiliary/dos/windows/ssh/sysax_sshd_kexchange.rb exploit
- https://www.mattandreko.com/2013/04/08/sysax-multi-server-6.10-ssh-dos/ exploittechnical-descriptionThird Party Advisory
- https://www.sysax.com/ product
- https://www.vulncheck.com/advisories/sysax-multi-server-sshd-key-exchange-dos third-party-advisoryThird Party Advisory
| Link | Providers | Tags |
|---|---|---|
| https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/auxiliary/dos/windows/ssh/sysax_sshd_kexchange.rb | exploit | |
| https://www.mattandreko.com/2013/04/08/sysax-multi-server-6.10-ssh-dos/ | exploittechnical-descriptionThird Party Advisory | |
| https://www.sysax.com/ | product | |
| https://www.vulncheck.com/advisories/sysax-multi-server-sshd-key-exchange-dos | third-party-advisoryThird Party Advisory |
Change history (0)
No recorded changes yet.