CVE-2026-7828— UltraVNC 数字错误漏洞

UltraVNC repeater integer overflow in win_log malloc leading to heap overflow

UltraVNC repeater through 1.8.2.2 contains an integer overflow in the HTTP request logging path. In repeater/webgui/settings.c:336, the win_log() function allocates list nodes via malloc(sizeof(struct LIST) + strlen(line)), where line is derived from HTTP request URIs. If strlen(line) is sufficiently large, the addition overflows to a value smaller than sizeof(struct LIST), causing a heap allocation smaller than required. The subsequent strcpy of the full string into the undersized allocation produces a heap buffer overflow. In the current implementation this overflow is bounded by the HTTP receive buffer size (WI_RXBUFSIZE = 153600 bytes, well below SIZE_MAX on 32-bit builds), limiting practical exploitability to a partial heap write. A remote unauthenticated attacker can trigger the theoretical overflow path by sending a maximally-sized URI in an HTTP request to the repeater HTTP port.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

整数溢出或超界折返

UltraVNC 数字错误漏洞

ultravnc是UltraVNC组织开源的一款用于Windows平台的开源远程终端控制软件。 UltraVNC 1.8.2.2及之前版本存在数字错误漏洞，该漏洞源于HTTP请求日志路径中的整数溢出，可能导致远程未经验证攻击者通过发送特制URI触发堆缓冲区溢出，造成部分堆写入。

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