CVE-2016-6581
7.5 · HIGHOverview
CVE-2016-6581 is a high-severity vulnerability affecting python hpack. It was published on January 10, 2017 and has a CVSS 3.0 base score of 7.5 (HIGH).
This vulnerability has a CVSS 3.0 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
A HTTP/2 implementation built using any version of the Python HPACK library between v1.0.0 and v2.2.0 could be targeted for a denial of service attack, specifically a so-called "HPACK Bomb" attack. This attack occurs when an attacker inserts a header field that is exactly the size of the HPACK dynamic header table into the dynamic header table. The attacker can then send a header block that is simply repeated requests to expand that field in the dynamic table. This can lead to a gigantic compression ratio of 4,096 or better, meaning that 16kB of data can decompress to 64MB of data on the target machine.
Remediation
Check the references section for vendor advisories and patches from python. Update hpack to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
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Frequently Asked Questions
What is CVE-2016-6581?
CVE-2016-6581 is a high-severity vulnerability affecting python hpack. It was published on January 10, 2017 and has a CVSS 3.0 base score of 7.5 (HIGH).
How severe is CVE-2016-6581?
This vulnerability has a CVSS 3.0 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2016-6581?
Check the references section for vendor advisories and patches from python. Update hpack to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2016-6581?
CyberStrike's AI-powered security agents can automatically detect CVE-2016-6581 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
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