Denial of Service (DoS) Affecting cryptography package, versions [0.8,41.0.3)


Severity

Recommended
0.0
medium
0
10

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

Threat Intelligence

EPSS
0.2% (58th percentile)

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  • Snyk IDSNYK-PYTHON-CRYPTOGRAPHY-5813746
  • published25 Jul 2023
  • disclosed19 Jul 2023
  • creditOSSfuzz

Introduced: 19 Jul 2023

CVE-2023-3446  (opens in a new tab)
CWE-400  (opens in a new tab)

How to fix?

Upgrade cryptography to version 41.0.3 or higher.

Overview

Affected versions of this package are vulnerable to Denial of Service (DoS) in the DH_check(), DH_check_ex() and EVP_PKEY_param_check() functions, which are used to check a DH key or DH parameters.

When the key or parameters that are being checked contain an excessively large modulus value (the p parameter) this may cause slowness in processing. Some checks use the supplied modulus value even if it has already been found to be too large.

The OpenSSL dhparam and pkeyparam command line applications are also vulnerable, when using the -check option.

NOTE: The OpenSSL SSL/TLS implementation is not affected by this issue.

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

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