Id:
CVE-2016-6581
Comment
:
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.
CVSSv2 Score:
7.8
Access vector:
|
NETWORK
|
Access complexity:
|
LOW
|
Authentication:
|
NONE
|
Confidentiality impact:
|
NONE
|
Integrity impact:
|
NONE
|
Availability impact:
|
COMPLETE
|
CVSSv2 Vector:
AV:N/AC:L/Au:N/C:N/I:N/A:C
CVSSv3 Score:
7.5
Attack vector:
|
NETWORK
|
Attack complexity:
|
LOW
|
Privileges required:
|
NONE
|
User interaction:
|
NONE
|
Scope:
|
UNCHANGED
|
Confidentiality impact:
|
NONE
|
Integrity impact:
|
NONE
|
Availability impact:
|
HIGH
|
CVSSv3 Vector:
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References: