Multiple Denial of Service (DoS) Vulnerabilities in HTTP/2 Disclosed (CVE-2019-9511, CVE-2019-9518)
A variety of Denial of Service vulnerabilities were found in third-party implementations of HTTP/2.
Background
On August 13, researchers at Netflix published an advisory for their GitHub page detailing their discovery of eight vulnerabilities in the HTTP/2 protocol implementations by third parties. The vulnerabilities were primarily discovered by Jonathan Looney, Engineering Manager at Netflix, with one vulnerability, CVE-2019-9518, discovered by Piotr Sikora, Senior Software Engineer at Google.
Image Credit: Cloudflare
Analisi
A client (“the attacker”) can exploit these HTTP/2 vulnerabilities by sending specially crafted requests to vulnerable servers. While these requests will vary, a vulnerable server will attempt to process the request and attempt to send a response. However, the malicious client ignores the response, leading to excess consumption of resources, which would result in a denial of service (DoS).
The following are the eight vulnerabilities and the associated nicknames given to them in the Netflix advisory.
| CVE ID | Nickname |
|---|---|
| CVE-2019-9511 | “Data Dribble” |
| CVE-2019-9512 | “Ping Flood” |
| CVE-2019-9513 | “Resource Loop” |
| CVE-2019-9514 | “Reset Flood” |
| CVE-2019-9515 | “Settings Flood” |
| CVE-2019-9516 | “0-Length Headers Leak” |
| CVE-2019-9517 | “Internal Data Buffering” |
| CVE-2019-9518 | “Empty Frames Flood” |
Proof of concept
At the time the blog was published, no proof-of-concept code was available.
Solution
To immediately address the vulnerabilities, Netflix’s advisory suggests disabling HTTP/2 support, but cautions that this could either result in performance degradation or not be feasible. Software vendors are in the process of publishing patches for these vulnerabilities. Initial reports from vendors can be found below:
| Vendor | Link(s) | Source |
|---|---|---|
| Akamai | HTTP2 Vulnerabilities | Blog |
| Ambassador (API Gateway) | Multiple HTTP/2 vulnerabilities in Envoy Proxy | Blog |
| Apache Traffic Server (ATS) | [ANNOUNCE] Apache Traffic Server is vulnerable to various HTTP/2 attacks | Mailing List |
| Cloudflare | On the recent HTTP/2 DoS attacks | Blog |
| Envoy (Proxy) | Version 1.11.1 History | Changelog |
| Google (Golang) | [security] Go 1.12.8 and Go 1.11.13 are released | Forum Posting |
| Microsoft | CVE-2019-9511, CVE-2019-9512, CVE-2019-9513, CVE-2019-9514, CVE-2019-9518 | Advisory |
| Netty Project | Netty 4.1.39.Final released | Blog |
| nghttp2 | nghttp2 v1.39.2 Release Notes | Software Release |
| Nginx | NGINX Updates Mitigate the August 2019 HTTP/2 Vulnerabilities | Blog |
| Node.js | August 2019 Security Releases | Blog |
| Swift | About the security content of SwiftNIO HTTP/2 1.5.0 | Advisory |
Customers using these software applications are encouraged to update to the patched versions as soon as possible.
Identifying affected systems
A list of Tenable plugins to identify these vulnerabilities will appear here as they’re released.
Get more information
Join Tenable's Security Response Team on the Tenable Community.
Learn more about Tenable, the first Cyber Exposure platform for holistic management of your modern attack surface.
Get a free 60-day trial of Tenable.io .
Articoli correlati
Cybersecurity Snapshot: Guide Unpacks Event-Logging Best Practices, as FAA Proposes Stronger Cyber Rules for Airplanes
August 23, 2024Looking to sharpen your team’s event logging and threat detection? A new guide offers plenty of best practices. Plus, the FAA wants airplanes to be more resilient to cyberattacks. Meanwhile, check out the critical vulnerabilities Tenable discovered in two Microsoft AI products. And get the latest on ransomware trends, vulnerability management practices and election security!
Cybersecurity Snapshot: EPA Urges Water Plants To Boost Cybersecurity, as OpenSSF Launches Threat Intel Platform for Open Source Software
May 24, 2024Check out the EPA’s call for water plants to beef up their cyber defenses. Plus, open source developers have a new platform to share threat intelligence. Moreover, business email compromise attacks prompt alert from U.K.’s cyber agency. And CISA tackles DNS encryption best practices. And much more!
Cybersecurity Snapshot: Want to Deploy AI Securely? New Industry Group Will Compile AI Safety Best Practices
December 15, 2023A group that includes the Cloud Security Alliance, CISA and Google is working to compile a comprehensive collection of best practices for secure AI use. Meanwhile, check out a draft of secure configuration recommendations for the Google Workspace suite. Plus, MITRE plans to release a threat model for embedded devices used in critical infrastructure. And much more!
Cybersecurity Snapshot: Guide Unpacks Event-Logging Best Practices, as FAA Proposes Stronger Cyber Rules for Airplanes
August 23, 2024Looking to sharpen your team’s event logging and threat detection? A new guide offers plenty of best practices. Plus, the FAA wants airplanes to be more resilient to cyberattacks. Meanwhile, check out the critical vulnerabilities Tenable discovered in two Microsoft AI products. And get the latest on ransomware trends, vulnerability management practices and election security!
SSRFing the Web with the Help of Copilot Studio
August 20, 2024Tenable Research discovered a critical information-disclosure vulnerability in Microsoft’s Copilot Studio via a server-side request forgery (SSRF), which allowed researchers access to potentially sensitive information regarding service internals with potential cross-tenant impact.
Cybersecurity Snapshot: First Quantum-resistant Algorithms Ready for Use, While New AI Risks’ Database Is Unveiled
August 16, 2024NIST has released the first encryption algorithms that can protect data against quantum attacks. Plus, MIT launched a new database of AI risks. Meanwhile, the CSA published a paper outlining the unique risks involved in building systems that use LLMs. And get the latest on Q2’s most prevalent malware, the Radar/Dispossessor ransomware gang and CVE severity assessments!
- Threat hunting
- Threat Intelligence
- Vulnerability Management
- Vulnerability Scanning