HTTP: Envoy HTTP Headers Denial of Service
This signature detects attempts to exploit a known vulnerability against Envoy Proxy. A successful attack can result in a denial-of-service condition.
Extended Description
Upon receiving each incoming request header data, Envoy will iterate over existing request headers to verify that the total size of the headers stays below a maximum limit. The implementation in versions 1.10.0 through 1.11.1 for HTTP/1.x traffic and all versions of Envoy for HTTP/2 traffic had O(n^2) performance characteristics. A remote attacker may craft a request that stays below the maximum request header size but consists of many thousands of small headers to consume CPU and result in a denial-of-service attack.
Affected Products
Envoyproxy envoy
References
CVE: CVE-2019-15226
Short Name
HTTP:CTS:ENVOY-HTTP-DOS
Severity
Major
Recommended
False
Recommended Action
Drop
Category
HTTP
Keywords
CVE-2019-15226 Denial Envoy HTTP Headers Service of
Release Date
12/30/2019
Supported Platforms
srx-branch-12.3
srx-19.3
srx-branch-19.3
vsrx3bsd-19.2
srx-branch-19.4
vsrx-19.4
mx-12.3
mx-19.4
vmx-19.4
mx-19.3
vsrx3bsd-19.4
srx-19.4
vsrx-12.3
vmx-19.3
vsrx-19.2
srx-12.3
Sigpack Version
3337
False Positive
Unknown
Vendors
Envoyproxy
CVSS Score
7.8