Proxygen
CVE-2019-11940
CRITICAL
Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Memory lifecycle management
MITRE ATT&CK
2 techniques across 2 tactics: Execution, Privilege Escalation The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 9.8 (CRITICAL). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. |
| Exploit ScenarioDerived | A remote attacker could access freed memory to execute arbitrary code or crash the application by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
In the course of decompressing HPACK inside the HTTP2 protocol, an unexpected sequence of header table resize operations can place the header table into a corrupted state, leading to a use-after-free. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Use After Free vulnerability could allow attackers to access freed memory to execute arbitrary code or crash the application.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Use smart pointers or garbage-collected languages. Set pointers to NULL after freeing. Enable memory sanitizers.
Affects your stack
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Technical ContextAI · show details
This vulnerability is classified as Use After Free (CWE-416), which allows attackers to access freed memory to execute arbitrary code or crash the application. In the course of decompressing HPACK inside the HTTP2 protocol, an unexpected sequence of header table resize operations can place the header table into a corrupted state, leading to a use-after-free condition and undefined behavior.29.0 until v2017.04.03.00. Affected products include: Facebook Proxygen.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
In the course of decompressing HPACK inside the HTTP2 protocol, an unexpected sequence of header table resize operations can place the header table into a corrupted state, leading to a use-after-free condition and undefined behavior. This issue affects Proxygen from v0.29.0 until v2017.04.03.00.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Use-after-free vulnerabilities occur when a program continues to access memory through a pointer after that memory has been deallocated.
Memory corruption occurs when a program writes data beyond the boundaries of allocated memory regions or accesses memory in unintended ways, violating the integrity of the process's address space.
Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.
Affected Products (CPE)NVD
Denial of service against HTTP/2 server implementations allows remote unauthenticated attackers to exhaust server resour
The SPDY/2 codec in Facebook Proxygen before 2015-11-09 truncates a certain field to two bytes, which allows hijacking a
A use-after-free is possible due to an error in lifetime management in the request adaptor when a malicious client invok
An out of bounds write is possible via a specially crafted packet in certain configurations of Proxygen due to improper
Facebook Proxygen before 2015-11-09 mismanages HTTPMessage.request state, which allows remote attackers to conduct hijac
The SPDY/2 codec in Facebook Proxygen before 2015-11-09 allows remote attackers to conduct hijacking attacks and bypass
Use-after-free in Meta's Proxygen HTTP library (v2024.10.28.00 through v2026.09.28.00) lets remote, unauthenticated atta
A packet of death scenario is possible in mvfst via a specially crafted message during a QUIC session, which causes a cr
An issue in the Proxygen handling of HTTP2 parsing of headers/trailers can lead to a denial-of-service attack. Rated hig
A potential denial-of-service issue in the Proxygen handling of invalid HTTP2 priority settings (specifically a circular
Proxygen fails to validate that a secondary auth manager is set before dereferencing it. Rated high severity (CVSS 7.5),
Use-after-free in Meta's proxygen C++ networking library (versions v2026.04.06.00 up to but not including v2026.09.28.00
Exploit-DB