GNU Binutils is a collection of various tools required to work with binary files, such as the linker and the assembler, widely used in the software development process. Recently, a vulnerability (CVE-2022-48064) has been discovered in the GNU Binutils versions before 2.40, related to excessive memory consumption through the function bfd_dwarf2_find_nearest_line_with_alt at dwarf2.c. This post aims to shed light on the exploit details, the code snippet, and the links to the original references, making it simple for the general audience to understand.

Vulnerability Overview

The vulnerability identified in the GNU Binutils is related to excessive memory consumption, which leads to an attack called a Denial of Service (DoS). Specifically, the vulnerability can be exploited by a potential attacker by supplying a crafted ELF (Executable and Linkable Format) file, which will trigger the issue within the bfd_dwarf2_find_nearest_line_with_alt function implementation at dwarf2.c in the GNU Binutils codebase.

A DoS attack aims to disrupt the regular functioning of a system or service by overwhelming it with requests or consuming system resources like memory or CPU to the point where it becomes inefficient or stops responding entirely. In this case, the excessive memory consumption vulnerability could be exploited to cause a DNS (Domain Name System) attack, having severe implications for the targeted systems or applications.

Code Snippet

Here is the code snippet of the vulnerable function bfd_dwarf2_find_nearest_line_with_alt within the dwarf2.c file in the GNU Binutils package:

bfd_boolean
_bfd_dwarf2_find_nearest_line_with_alt
...
{
  ...
  while (1)
    {
      ...
      case DW_TAG:
        ...
      case DW_TAG_compile_unit:
        ...
      case DW_TAG_partial_unit:
        {
          ...
          info_ptr = hdr->line_range ? read_and_display_attr_value (abfd, attr_form, attr_name, u, hdr, comp_unit_die, info_ptr, &prefix, sec, NULL, TRUE, diecount) : info_ptr;
          ...
        }
      ...
    }
  ...
}

The vulnerability is present because of improper handling of specific attributes within the loop, causing excessive memory consumption and eventually allowing an attacker to cause a DoS attack.

Exploit Details

To exploit this vulnerability, the attacker has to craft a specific ELF file with malicious payload and attributes that trigger the excessive memory consumption behavior in the _bfd_dwarf2_find_nearest_line_with_alt function. Once the crafted ELF file is processed by the affected GNU Binutils package, it may lead to an excessive memory consumption, which will result in a denial of service condition.

Original References

1. CVE-2022-48064 - National Vulnerability Database: https://nvd.nist.gov/vuln/detail/CVE-2022-48064
2. GNU Binutils Project Home: https://www.gnu.org/software/binutils/

Conclusion

In conclusion, the excessive memory consumption vulnerability (CVE-2022-48064) detected in the GNU Binutils before version 2.40 highlights yet another attack vector that could potentially disrupt systems and services. It is essential for users and developers using the GNU Binutils package to update their software to the latest version to mitigate the risk associated with this vulnerability. In addition, it's always a good practice to keep an eye on the official updates and announcements from the GNU Binutils project for any further issues.

Timeline

Published on: 08/22/2023 19:16:30 UTC
Last modified on: 11/07/2023 03:56:28 UTC