CVE-2023-1972 is a vulnerability discovered in a potential heap-based buffer overflow within _bfd_elf_slurp_version_tables() in the bfd/elf.c file. This security flaw may cause loss of availability in affected systems.

In this long read post, we will closely examine the scope and impact of the vulnerability, the exploit details and potential attack vectors, and provide links to the original references for those interested in further investigation.

Description

A heap-based buffer overflow occurs when data is written to memory, exceeding the expected boundaries of the buffer, which subsequently compromises adjacent memory locations within the heap. This type of buffer overflow potentially leads to unpredictable behavior in the affected system, including crashes, data corruption, and other kinds of instability.

The vulnerability CVE-2023-1972 is found in the _bfd_elf_slurp_version_tables() function within the bfd/elf.c file. This function's role is to parse version information from ELF files, which is used by the linker to generate the final executable or library. The vulnerability was discovered during a routine code audit and affects multiple platforms due to its presence in a widely used codebase.

Buffer overflow vulnerabilities like CVE-2023-1972 can have numerous potential consequences, depending on how the overrun memory is used or managed. The most severe outcome would be arbitrary code execution, where an attacker could gain control over the affected system. Other consequences include denial of service, memory disclosure, and privilege escalation.

Exploit Details

At the core of the vulnerability is the improper handling of memory allocation and resizing for version information arrays within the _bfd_elf_slurp_version_tables() function. The code snippet below highlights the affected lines of code:

`c
/* bfd/elf.c */
static bfd_boolean
_bfd_elf_slurp_version_tables (bfd *abfd, bfd_boolean default_imported)
{
   // ...
   while (ext_versym != NULL && offset < ext_versym_end)
   {
       // ...

       if (type > cnt)
       {
           if (type > VERS_MAX * cnt)
           {

Timeline

Published on: 05/17/2023 22:15:00 UTC
Last modified on: 06/02/2023 17:40:00 UTC