Denial of Service (DoS) Affecting cryptography package, versions [,39.0.1)


Severity

Recommended
0.0
medium
0
10

CVSS assessment made by Snyk's Security Team

    Threat Intelligence

    EPSS
    0.19% (57th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk ID SNYK-PYTHON-CRYPTOGRAPHY-3316038
  • published 9 Feb 2023
  • disclosed 7 Feb 2023
  • credit Kurt Roeckx

How to fix?

Upgrade cryptography to version 39.0.1 or higher.

Overview

Affected versions of this package are vulnerable to Denial of Service (DoS) due to a null dereference when validating DSA public keys in the EVP_PKEY_public_check() function.

NOTE: The TLS implementation in OpenSSL does not call this function.

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
Expand this section

Snyk

Recommended
5.9 medium
  • Attack Vector (AV)
    Network
  • Attack Complexity (AC)
    High
  • Privileges Required (PR)
    None
  • User Interaction (UI)
    None
  • Scope (S)
    Unchanged
  • Confidentiality (C)
    None
  • Integrity (I)
    None
  • Availability (A)
    High
Expand this section

NVD

7.5 high
Expand this section

SUSE

7.5 high
Expand this section

Red Hat

7.5 high