CVE-2026-7839
CriticalCVSS 9.1Exploitation Probability (EPSS)
Low risk29th percentile - higher than 29% of all known CVEs
Summary
UltraVNC repeater up to version 1.8.2.2 initializes the HTTP administration server with a hardcoded default password. On first run, when settings2.txt is absent, it writes the literal string "adminadmi2" as the admin password. The HTTP Basic-auth handler checks this password without rate-limiting or lockout.
Risk Assessment
Any remote attacker who can reach the repeater HTTP port (default TCP 80) can authenticate as administrator using the well-known default credential on a fresh or unmodified installation, gaining full control of the repeater configuration including allow/deny rules and session visibility.
Recommendation
Immediately change the default admin password after the first run and consider restricting access to the HTTP port to trusted IP addresses or implementing additional authentication.
Original NVD description (English source)
UltraVNC repeater through 1.8.2.2 initializes the HTTP administration server with a hardcoded default password. In repeater/webgui/settings.c:197, when settings2.txt is absent on first run the repeater writes the literal string "adminadmi2" as the admin password via strcpy_s(saved_password, 64, "adminadmi2"). The HTTP Basic-auth handler wi_decode_auth() checks this password without rate-limiting or lockout. Any remote attacker who can reach the repeater HTTP port (default TCP 80) can authenticate as administrator using the well-known default credential on a fresh or unmodified installation, gaining full control of the repeater configuration including allow/deny rules and session visibility.