Vulnerability identifier: #VU35171
Vulnerability risk: Medium
CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]
CVE-ID:
CWE-ID:
CWE-400
Exploitation vector: Network
Exploit availability: No
Vulnerable software:
envoy
Server applications /
IDS/IPS systems, Firewalls and proxy servers
Vendor: Cloud Native Computing Foundation
Description
The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.
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.
Mitigation
Install update from vendor's website.
Vulnerable software versions
envoy: 1.0.0 - 1.11.2
External links
http://github.com/envoyproxy/envoy/commit/afc39bea36fd436e54262f150c009e8d72db5014
http://github.com/envoyproxy/envoy/commits/master
http://github.com/envoyproxy/envoy/issues/8520
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.