Vulnerability · Published Aug 13, 2025 · Assigned by VulDB
CVE-2025-8760INSTAR 2K+/4K fcgi_server base64_decode buffer overflow
Critical 9.8
In plain English
A critical-severity buffer overflow in 2K+ from INSTAR. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 59% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code.
Severity (CVSS 3.1)9.8Critical
Exploit odds (30 days)0.9%top 40.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack tooling1Public PoC
Official 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.
Affected products (as reported)
Weakness: CWE-120, CWE-119 · Vector: 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
References
- VDB-319863 | INSTAR 2K+/4K fcgi_server base64_decode buffer overflow vdb-entry, technical-description
- VDB-319863 | CTI Indicators (IOB, IOC, IOA) signature, permissions-required
- https://modzero.com/static/MZ-25-03_modzero_INSTAR.pdf related