CVE-2022-48063 is an important security vulnerability that affects the GNU Binutils package before version 2.40. This vulnerability is specifically related to excessive memory consumption vulnerability via the function load_separate_debug_files in the dwarf2.c file. An attacker can exploit this vulnerability by crafting a malicious ELF (Executable and Linkable Format) file, potentially causing a Denial of Service (DoS) attack. In this article, we will discuss the details of this vulnerability, how it affects the GNU Binutils, and how the attack can be carried out. We will also provide code snippets and links to original references for a better understanding of the issue.

Understanding GNU Binutils and ELF Files

GNU Binutils is a collection of binary tools (utilities) that are essential for working with executable files on the GNU operating system. These tools are widely used to manipulate, inspect, and analyze object files and executables.

ELF (Executable and Linkable Format) is a common standard file format for executables, object code, shared libraries, and core dumps. ELF files are mainly used on Unix-based operating systems, and GNU Binutils rely on handling these files to perform various actions.

The Vulnerability: Excessive Memory Consumption

The vulnerability lies in the GNU Binutils packages before version 2.40, where the load_separate_debug_files function in the dwarf2.c file can consume excessive memory when parsing a maliciously crafted ELF file. This excessive memory consumption can lead to a Denial of Service (DoS) attack, with the potential to cause a system crash or, in the worst case, a complete system shutdown.

Here's a code snippet showcasing the load_separate_debug_files function in the dwarf2.c file

static void
load_separate_debug_files (bfd *abfd ATTRIBUTE_UNUSED)
{
  ...
  debug_filename[base_len] = '-';
  /* Now iterate over all possible file numbers.  */
  for (debug_file_id = 1; ; ++debug_file_id)
    {
      bfd *debug_bfd;

      sprintf (debug_filename + base_len + 1, "%u", debug_file_id);
      debug_bfd = bfd_openr (debug_filename, dummy_target);
      ...
    }
}

Exploit Details

The attack is carried out by crafting an ELF file designed to overwhelm the load_separate_debug_files function. This malicious file can then be supplied to one of the GNU Binutils tools, such as readelf, objdump, or nm.

Below is an example of how an attacker could use readelf to exploit the vulnerability

$ readelf -w malicious.elf

When the function parses the crafted ELF file, it consumes excessive memory to store various data structures, causing the tool to hang or fail to work properly, which in turn can lead to a Denial of Service (DoS) attack.

- National Vulnerability Database: CVE-2022-48063
- SecurityTracker: ID 1044606
- GitHub Security Advisory: GHSA-99vw-xg7w-4gx2

Conclusion

CVE-2022-48063 is a critical vulnerability that affects GNU Binutils before version 2.40 and has the potential to cause significant harm through a Denial of Service attack. To mitigate this vulnerability, it is crucial for developers and system administrators to apply the necessary patches and update their GNU Binutils packages accordingly. By understanding the details of this vulnerability and how it affects the GNU Binutils, we can better grasp its potential impact and take the necessary actions to protect our systems and software.

Timeline

Published on: 08/22/2023 19:16:30 UTC
Last modified on: 10/06/2023 15:15:13 UTC