Sysax Multi Server < 5.55 SSH Username Buffer Overflow
Published Aug 13, 2025
9.3
CRITICALCVSS 4.0
EPSS 3.02%
Description
Sysax Multi Server versions prior to 5.55 contain a stack-based buffer overflow in its SSH service. When a remote attacker supplies an overly long username during authentication, the server copies the input to a fixed-size stack buffer without proper bounds checking. This allows remote code execution under the context of the service.
Affected products
-
- Version 0StatusaffectedConstraints<5.55
- 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 |
|
- < 5.55
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:H/VI:H/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:H/VI:H/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:H/I:H/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
TotalDecision
n/aAssessed Aug 14, 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 (8 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 3.02% (0.03018) | 86.97th | v5 (v2026.06.15) |
| Jun 15, 2026 | 2.84% (0.02840) | 84.78th | v5 (v2026.06.15) |
| Jun 9, 2026 | 79.48% (0.79483) | 99.11th | v4 (v2025.03.14) |
| Jan 9, 2026 | 69.68% (0.69676) | 98.60th | v4 (v2025.03.14) |
| Dec 13, 2025 | 75.21% (0.75213) | 98.83th | v4 (v2025.03.14) |
| Oct 8, 2025 | 72.58% (0.72581) | 98.70th | v4 (v2025.03.14) |
| Sep 25, 2025 | 4.13% (0.04125) | 88.17th | v4 (v2025.03.14) |
| Aug 14, 2025 | 0.70% (0.00701) | 71.05th | v4 (v2025.03.14) |
References (7)
- https://advisories.checkpoint.com/defense/advisories/public/2012/cpai-23-sepc.html third-party-advisoryThird Party Advisory
- https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/windows/ssh/sysax_ssh_username.rb exploitThird Party Advisory
- https://web.archive.org/web/20120302203344/http://www.pwnag3.com/2012/02/sysax-multi-server-ssh-username-exploit.html technical-descriptionexploitThird Party Advisory
- https://www.exploit-db.com/exploits/18535 exploitVDB Entry
- https://www.exploit-db.com/exploits/18557 exploitVDB Entry
- https://www.sysax.com/ product
- https://www.vulncheck.com/advisories/sysax-multi-server-ssh-username-buffer-overflow third-party-advisoryThird Party Advisory
| Link | Providers | Tags |
|---|---|---|
| https://advisories.checkpoint.com/defense/advisories/public/2012/cpai-23-sepc.html | third-party-advisoryThird Party Advisory | |
| https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/windows/ssh/sysax_ssh_username.rb | exploitThird Party Advisory | |
| https://web.archive.org/web/20120302203344/http://www.pwnag3.com/2012/02/sysax-multi-server-ssh-username-exploit.html | technical-descriptionexploitThird Party Advisory | |
| https://www.exploit-db.com/exploits/18535 | exploitVDB Entry | |
| https://www.exploit-db.com/exploits/18557 | exploitVDB Entry | |
| https://www.sysax.com/ | product | |
| https://www.vulncheck.com/advisories/sysax-multi-server-ssh-username-buffer-overflow | third-party-advisoryThird Party Advisory |
Change history (0)
No recorded changes yet.