# CVE-2016-6298: jwcrypto lacks the Random Filling protection mechanism

Source: https://junglewise.ai/threats/cve-2016-6298-jwcrypto-lacks-the-random-filling-protection-mechanism  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2016-09-01  
License: CC BY 4.0 with a link back

CVE-2016-6298 · Severity: low · CVSS 3 · Published 2016-09-01

The _Rsa15 class in the RSA 1.5 algorithm implementation in jwa.py in jwcrypto before 0.3.2 lacks the Random Filling protection mechanism, which makes it easier for remote attackers to obtain cleartext data via a Million Message Attack (MMA).

Technologies: [jwcrypto (PyPI)](https://junglewise.ai/threats/technologies/jwcrypto). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2016-6298 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2016-6298 being exploited in the wild.

**How severe is CVE-2016-6298?** Low severity, with a CVSS score of 3, published 1 September 2016.

**Which products and versions are affected?** jwcrypto (PyPI) ECOSYSTEM:introduced=0,fixed=0.3.2, GIT:introduced=0,fixed=eb5be5bd94c8cae1d7f3ba9801377084d8e5a7ba|ECOSYSTEM:introduced=0,fixed=0.4.0.

**Is there a fix for CVE-2016-6298?** Yes. jwcrypto (PyPI): upgrade to 0.3.2, 0.4.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2016-6298?** Check whether you run jwcrypto (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- jwcrypto (PyPI): upgrade to 0.3.2, 0.4.0 or later

  ```sh
  pip install "jwcrypto>=0.4.0"
  ```


## Affected products

- jwcrypto (PyPI) ECOSYSTEM:introduced=0,fixed=0.3.2, GIT:introduced=0,fixed=eb5be5bd94c8cae1d7f3ba9801377084d8e5a7ba|ECOSYSTEM:introduced=0,fixed=0.4.0

## Identifiers

- CVE-2016-6298
- GHSA-wg33-x934-3ghh
- PYSEC-2016-4

## Related threats

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- [PYSEC-2026-827 - jwcrypto token substitution can lead to authentication bypass](https://junglewise.ai/threats/cve-2022-3102-jwcrypto-token-substitution-can-lead-to-authentication-bypass)
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- [DoS with algorithms that use PBKDF2 due to unbounded PBES2 Count value](https://junglewise.ai/threats/cve-2023-6681-dos-with-algorithms-that-use-pbkdf2-due-to-unbounded-pbes2-count)