{ "CVE_data_meta": { "ASSIGNER": "cve@mitre.org", "ID": "CVE-2016-6581", "STATE": "PUBLIC" }, "affects": { "vendor": { "vendor_data": [ { "product": { "product_data": [ { "product_name": "n/a", "version": { "version_data": [ { "version_value": "n/a" } ] } } ] }, "vendor_name": "n/a" } ] } }, "data_format": "MITRE", "data_type": "CVE", "data_version": "4.0", "description": { "description_data": [ { "lang": "eng", "value": "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." } ] }, "problemtype": { "problemtype_data": [ { "description": [ { "lang": "eng", "value": "n/a" } ] } ] }, "references": { "reference_data": [ { "name": "92315", "refsource": "BID", "url": "http://www.securityfocus.com/bid/92315" }, { "name": "https://python-hyper.org/hpack/en/latest/security/CVE-2016-6581.html", "refsource": "CONFIRM", "url": "https://python-hyper.org/hpack/en/latest/security/CVE-2016-6581.html" } ] } }