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CVE-2025-8760
INSTAR 2K+/4K fcgi_server base64_decode buffer overflow
Critical9.3EPSS 0.87%
- Published
- Updated
- Reserved
- Assigned by
- VulDB
Description
A vulnerability was identified in INSTAR 2K+ and 4K 3.11.1 Build 1124. This affects the function base64_decode of the component fcgi_server. The manipulation of the argument Authorization leads to buffer overflow. It is possible to initiate the attack remotely.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulDBCNA (assigner) | 4.0 | Critical9.3 | 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 |
| VulDBCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:X/RL:W/RC:R |
| VulDBCNA (assigner) | 3.0 | Critical9.8 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:X/RL:W/RC:R |
| VulDBCNA (assigner) | 2.0 | Critical10.0 | AV:N/AC:L/Au:N/C:C/I:C/A:C/E:ND/RL:W/RC:UR |
| NVDNVD · Deferred | 4.0 | Critical9.3 | 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 |
- EPSS (exploitation in 30 days)
- 0.87% · top 41% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: total
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The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.3.
Weakness
Affected products
References (3)
- VDB-319863 | INSTAR 2K+/4K fcgi_server base64_decode buffer overflow (opens in a new tab)vdb-entrytechnical-description
- VDB-319863 | CTI Indicators (IOB, IOC, IOA) (opens in a new tab)signaturepermissions-required
- https://modzero.com/static/MZ-25-03_modzero_INSTAR.pdf (opens in a new tab)related
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2025-8760)Record last updated .