vulnerability

Juniper Junos OS: 2021-04 Security Bulletin: Junos OS: Multiple HTTP/2 vulnerabilities are resolved in remote procedure calls using gRPC remote procedure calls (gRPC) framework (JSA11167) (multiple CVEs)

Severity
8
CVSS
(AV:N/AC:L/Au:N/C:N/I:N/A:C)
Published
Aug 13, 2019
Added
Apr 16, 2021
Modified
Mar 27, 2026

Description

Some HTTP/2 implementations are vulnerable to window size manipulation and stream prioritization manipulation, potentially leading to a denial of service. The attacker requests a large amount of data from a specified resource over multiple streams. They manipulate window size and stream priority to force the server to queue the data in 1-byte chunks. Depending on how efficiently this data is queued, this can consume excess CPU, memory, or both.

Solution

juniper-junos-os-upgrade-latest

References

    Title
    Rapid7 Labs

    2026 Global Threat Landscape Report

    The predictive window has collapsed. Exploitation follows disclosure in days. See how attackers are accelerating and how to stay ahead.