SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2016-6580

A HTTP/2 implementation built using any version of the Python priority library prior to version 1.2.0 could be targeted by a malicious peer by having that peer assign priority information for every possible HTTP/2 stream ID.

HIGH 7.5EPSS 1.81%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.81%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

A HTTP/2 implementation built using any version of the Python priority library prior to version 1.2.0 could be targeted by a malicious peer by having that peer assign priority information for every possible HTTP/2 stream ID. The priority tree would happily continue to store the priority information for each stream, and would therefore allocate unbounded amounts of memory. Attempting to actually use a tree like this would also cause extremely high CPU usage to maintain the tree.

CVSS 3.0
7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
1.81% probability · 77th percentile
CISA KEV
Not listed
Weakness
CWE-399
Affected
python/python priority library
Source
cve@mitre.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.