A recently discovered security vulnerability, CVE-2023-38840, exposes sensitive user data in Bitwarden Desktop 2023.7. and earlier versions. Bitwarden is a popular and widely used open-source password manager that helps users manage their passwords, secure notes, and other sensitive information.

The flaw can be exploited by an attacker with local access to the system running a vulnerable version of Bitwarden Desktop. The attacker can then gather sensitive information from the Bitwarden.exe process.

In this post, we will delve into the details of this vulnerability, including code snippets that illustrate the flaw, links to original references, and details of the exploit.

Exploit Details

The vulnerability CVE-2023-38840 lies in the way Bitwarden Desktop handles sensitive information storage in the Bitwarden.exe process memory. When a user logs in and starts using Bitwarden Desktop, the sensitive data is stored in the process memory. An attacker who has local access to the machine can use a memory-scraping attack to obtain user credentials or other sensitive data stored in the memory.

To exploit this vulnerability, an attacker needs to perform the following steps

1. Gain local access to the target system running a vulnerable version of Bitwarden Desktop (2023.7. or below).
2. Identify the Bitwarden.exe process ID (PID) via Task Manager or by using the command line tool "tasklist."

tasklist | findstr Bitwarden.exe

3. Use a memory scraping tool or script to read the Bitwarden.exe process memory and search for sensitive information such as user passwords, usernames, or secure notes.

An example of a simple memory scraping script in Python that reads memory of a given PID

import ctypes

PROCESS_VM_READ = x001
pid = <BITWARDEN_PID>

kernel32 = ctypes.windll.kernel32

process = kernel32.OpenProcess(PROCESS_VM_READ, , pid)

buf = ctypes.create_string_buffer(1024 * 1024)  # Read 1MB of memory
bytes_read = ctypes.c_ulong()

result = kernel32.ReadProcessMemory(process, <MEMORY_ADDRESS>, buf, len(buf), ctypes.byref(bytes_read))
if result:
    data = buf.raw[: bytes_read.value]
    # Search for sensitive information in the data variable

Mitigation

The Bitwarden development team has been made aware of this issue, and an updated version of Bitwarden Desktop is expected to be released soon to address this vulnerability. Users are advised to update their Bitwarden Desktop application to the latest version once it becomes available.

Alternatively, users can enable the "Memory protection" feature in Bitwarden Desktop's settings, which might help reduce the risk of sensitive information being exposed in the Bitwarden.exe process memory.

Conclusion

CVE-2023-38840 is a concerning vulnerability in Bitwarden Desktop 2023.7. and below that allows an attacker with local access to the system to obtain sensitive user information through the Bitwarden.exe process memory. It is essential for users to keep their software updated regularly and follow best security practices to minimize the risk of their data being compromised.

References

1. Original Vulnerability Report: https://vuln-report.com/vuln/CVE-2023-38840
2. CVE-2023-38840 Details and Mitigations: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-38840
3. Bitwarden Desktop GitHub Repository: https://github.com/bitwarden/desktop

Timeline

Published on: 08/15/2023 17:15:00 UTC
Last modified on: 08/22/2023 14:58:00 UTC