CVE-2023-44487 Vulnerability
Written by: Monica Burgess
Published: 11/07/25
CVE-2023-44487 is a critical vulnerability categorized as a Denial-of-Service (DoS) exploit. It targets HTTP/2 protocol implementations, allowing attackers to overwhelm servers with malicious requests, leading to service disruptions. This vulnerability is particularly concerning due to its widespread impact on web servers and cloud services.
When was it Discovered?
CVE-2023-44487 was disclosed on October 10, 2023, by security researchers at Google and Cloudflare. The vulnerability was publicly documented shortly after, with advisories issued by major vendors to mitigate its impact.
Affected Products & Versions
Product | Versions Affected | Fixed Versions / Patch Links |
Apache HTTP Server | 2.4.54 and below | Patch Link |
NGINX | 1.25.0 and below | Patch Link |
Microsoft IIS | All versions | Patch Link |
CVE-2023-44487 Technical Description
CVE-2023-44487 exploits a flaw in the HTTP/2 protocol, specifically in how it handles stream multiplexing. Attackers can send a flood of crafted requests that consume server resources, leading to a denial-of-service condition. The vulnerability arises from improper input validation and resource allocation, making it possible to exhaust memory and CPU resources.
Tactics, Techniques & Procedures (TTPs)
Attackers leverage this vulnerability by sending a high volume of HTTP/2 requests with malicious payloads. These requests exploit the server's inability to handle excessive streams, causing resource exhaustion.
Indicators of Compromise
Unusual spikes in HTTP/2 traffic volume.
High CPU and memory usage on web servers.
Logs showing repeated malformed HTTP/2 requests.
Known Proof-of-Concepts & Exploits
Proof-of-concept exploits for CVE-2023-44487 have been published on platforms like GitHub. Active exploitation campaigns have been observed targeting unpatched servers, particularly in cloud environments.
How to Detect CVE-2023-44487 Vulnerability?
Organizations can detect CVE-2023-44487 by monitoring HTTP/2 traffic for anomalies. SIEM tools can be configured with detection rules to identify malicious patterns. Sample log queries and host-based detection signatures are available from major security vendors.
Impact & Risk of CVE-2023-44487 Vulnerability
The CVE-2023-44487 vulnerability poses a significant risk to business continuity. Exploitation can lead to prolonged service outages, affecting data availability and customer trust. In severe cases, it can disrupt critical infrastructure relying on HTTP/2.
Mitigation & Remediation Strategies
To mitigate CVE-2023-44487, organizations should:
Apply vendor patches immediately.
Implement rate-limiting on HTTP/2 requests.
Use web application firewalls (WAFs) to block malicious traffic.
Monitor server performance and traffic patterns for anomalies.
CVE-2023-44487 Vulnerability FAQs
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