漏洞标题
Grub2: ufs: 处理符号链接时可能发生整数溢出导致基于堆的越界写入
漏洞描述信息
在grub2中发现了一个漏洞。当执行符号链接查找时,grub的UFS模块会根据inode的数据大小来分配内部缓冲区以读取文件内容,但是它未能检查符号链接的数据大小是否溢出。当这种情况发生时,grub_malloc()可能会被调用,并传递一个比实际需要的值更小的值。在进一步从磁盘读取数据到缓冲区时,grub_ufs_lookup_symlink()函数将会写入超出分配大小的区域。攻击者可以通过构造恶意文件系统来利用此漏洞,从而破坏堆中存储的数据,允许执行任意代码,用于绕过安全启动机制。
CVSS信息
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
漏洞类别
跨界内存写
漏洞标题
Grub2: ufs: integer overflow may lead to heap based out-of-bounds write when handling symlinks
漏洞描述信息
A flaw was found in grub2. When performing a symlink lookup, the grub's UFS module checks the inode's data size to allocate the internal buffer to read the file content, however, it fails to check if the symlink data size has overflown. When this occurs, grub_malloc() may be called with a smaller value than needed. When further reading the data from the disk into the buffer, the grub_ufs_lookup_symlink() function will write past the end of the allocated size. An attack can leverage this by crafting a malicious filesystem, and as a result, it will corrupt data stored in the heap, allowing for arbitrary code execution used to by-pass secure boot mechanisms.
CVSS信息
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
漏洞类别
跨界内存写