There is an issue with grub2 before version 2.06 while handling symlink on ext filesystems. A filesystem containing a symbolic link with an inode size of UINT32_MAX causes an arithmetic overflow leading to a zero-sized memory allocation with subsequent heap-based buffer overflow.
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
| Link | Tags |
|---|---|
| https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-14311 | issue tracking third party advisory |
| https://usn.ubuntu.com/4432-1/ | third party advisory vendor advisory |
| http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00017.html | mailing list third party advisory vendor advisory |
| http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00016.html | mailing list third party advisory vendor advisory |
| https://security.gentoo.org/glsa/202104-05 | third party advisory vendor advisory |
| http://www.openwall.com/lists/oss-security/2021/09/17/2 | third party advisory mailing list |
| http://www.openwall.com/lists/oss-security/2021/09/17/4 | third party advisory mailing list |
| http://www.openwall.com/lists/oss-security/2021/09/21/1 | third party advisory mailing list |