# CVE-2016-7544: Crypto++ invalid memory deallocation in AES implementation

Source: https://junglewise.ai/threats/cve-2016-7544-crypto-invalid-memory-deallocation-in-aes-implementation  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2017-01-30. Updated: 2026-05-14  
License: CC BY 4.0 with a link back

CVE-2016-7544 · Severity: high · CVSS 7.5 · Published 2017-01-30

Crypto++ is a widely used open-source library for cryptographic functions. A flaw in how the library manages memory on Windows systems can cause applications using it to crash. This could allow an attacker to disrupt services or cause a denial-of-service condition for software that relies on this library for encryption tasks.

Technologies: [Microsoft Windows](https://junglewise.ai/threats/technologies/windows). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2016-7544 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2016-7544 being exploited in the wild.

**How severe is CVE-2016-7544?** High severity, with a CVSS score of 7.5, published 30 January 2017.

**Which products and versions are affected?** Crypto++ Project Crypto++ 5.6.4.

**Is there a fix for CVE-2016-7544?** A patch was published on 2016-10-11: Fixed in Crypto++ 5.6.5 release Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2016-7544 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2016-7544?** Check whether you run Microsoft Windows. 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.

## Technical details

A memory management error exists in the AES implementation of Crypto++ 5.6.4 when compiled with Microsoft Visual C++ (_MSC_VER). The library utilizes _malloca to allocate memory and subsequently adjusts the pointer to a 256-byte boundary to align tables and mitigate cache timing attacks. However, the code incorrectly passes this adjusted pointer to _freea instead of the original pointer returned by _malloca. This violation of the _malloca/_freea contract leads to an invalid free operation, typically resulting in a heap corruption or application crash. The issue is specific to Windows environments and was resolved in version 5.6.5.

## Affected products

- Crypto++ Project Crypto++ 5.6.4

## Timeline

- 2016-09-22: disclosed: Issue reported to oss-security mailing list
- 2016-09-23: advisory: CVE-2016-7544 assigned
- 2017-01-30: advisory: NVD publication date
- 2016-10-11: patched: Fixed in Crypto++ 5.6.5 release

## References

- [http://www.openwall.com/lists/oss-security/2016/09/23/5](http://www.openwall.com/lists/oss-security/2016/09/23/5)
- [http://www.openwall.com/lists/oss-security/2016/09/23/9](http://www.openwall.com/lists/oss-security/2016/09/23/9)
- [http://www.securityfocus.com/bid/93164](http://www.securityfocus.com/bid/93164)
- [https://github.com/weidai11/cryptopp/issues/302](https://github.com/weidai11/cryptopp/issues/302)
- [https://www.cryptopp.com/release565.html](https://www.cryptopp.com/release565.html)

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