Denial of Service (DoS) Affecting cryptography package, versions [2.5,41.0.4)


Severity

Recommended
0.0
medium
0
10

CVSS assessment made by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.04% (12th percentile)

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  • Snyk IDSNYK-PYTHON-CRYPTOGRAPHY-5914629
  • published10 Sept 2023
  • disclosed8 Sept 2023
  • creditZach Wilson, Bernd Edlinger

Introduced: 8 Sep 2023

CVE-2023-4807  (opens in a new tab)
CWE-400  (opens in a new tab)

How to fix?

Upgrade cryptography to version 41.0.4 or higher.

Overview

Affected versions of this package are vulnerable to Denial of Service (DoS). The POLY1305 MAC (message authentication code) implementation might corrupt the internal state of applications on the Windows 64 platform when running on newer X86_64 processors supporting AVX512-IFMA instructions. If an attacker can influence whether the POLY1305 MAC algorithm is used in an application, the application state might be corrupted with various application dependent consequences, the most likely of which being denial of service. The maintainers are currently not aware of any concrete application that would be affected by this issue.

NOTES:

This vulnerability is only exploitable on Windows.

The FIPS provider is not affected by this issue.

Workaround

Disable AVX512-IFMA instructions by setting the environment variable OPENSSL_ia32cap: OPENSSL_ia32cap=:~0x200000

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

  • High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

  • Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

CVSS Scores

version 3.1