Threats / IETF / CVE-2023-44487
CVE-2023-44487
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
IETF HTTP/2 vulnerability
HTTP/2 rapid reset vulnerability enables distributed denial-of-service attacks through stream cancellation abuse, allowing attackers to exhaust server resources with minimal bandwidth.
Verdict
Today item — known-exploited.
A resource exhaustion flaw in HTTP/2 stream handling permits remote attackers to trigger denial-of-service conditions by rapidly resetting streams, bypassing rate-limiting protections and affecting availability of web services.
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Public proof-of-concept exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
22 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-10-10).
Probability (EPSS)
EPSS 0.99999 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: IETF, HTTP/2. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-400 Uncontrolled Resource Consumption — weakness family: Resource / availability.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft HTTP/2 requests with rapid stream resets to consume server CPU and memory resources.
Business
Web service availability degrades as infrastructure becomes unable to process legitimate traffic.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I distribute this attack across multiple sources to amplify the resource consumption impact.
Business
Operational costs spike due to emergency scaling and incident response while revenue-generating services remain offline.
3
Lateral reach — past segmentation narrative 3
Attacker
I exploit the low bandwidth requirement to launch attacks from constrained networks or IoT devices.
Business
Attack surface expands beyond traditional DDoS sources, complicating mitigation and defense strategies.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05