Yüksek CVSS 7.6
CVE-2026-7831: Ultravnc: güvenlik açığı
Açıklama (NVD)
UltraVNC viewer through 1.8.2.2 contains an off-by-one stack buffer overflow in the RFB ServerInit message handler. In vncviewer/ClientConnection.cpp, when the server-supplied nameLength equals exactly 2024 the code declares a 2024-byte stack buffer _dn[2024] and calls ReadString(_dn, 2024). ReadString writes the NUL terminator at buf[length], i.e., _dn[2024], one byte past the end of the stack buffer. A malicious VNC server can trigger this condition by advertising a desktop name of length 2024 in its ServerInit message. On release builds without stack canaries the single-byte NUL overwrite adjacent stack data. On builds with /GS stack protection the canary is corrupted and the process terminates, resulting in denial of service. User interaction (connecting the viewer to the malicious server) is required.
Özet bilgiler
- Ürün
- Uvnc Ultravnc
- CVSS v3.1
- 7.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H - EPSS
- %0,74 (yüzdelik 55)
- CWE
- CWE-193
- Yama
- Yok / bilinmiyor
Etkilenen sürümler
| Ürün | Başlangıç | Bitiş | Düzeltildi |
|---|---|---|---|
| uvnc-ultravnc | — | 1.8.2.2 | — |