Use-after-free in envoy - CVE-2021-32781
Published: August 26, 2021
Vulnerability identifier: #VU56107
CSH Severity: Medium
CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2021-32781
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a use-after-free error when processing HTTP requests and responses in Envoy. A remote attacker can send a specially crafted HTTP request or response to the application, trigger a use-after-free error and perform a denial of service attack.
Successful exploitation of the vulnerability requires presence of extension that can modify and increase the size of request or response bodies.
Affected software
envoy
Istio
servicemesh-proxy (Red Hat package)
servicemesh (Red Hat package)
Istio
servicemesh-proxy (Red Hat package)
servicemesh (Red Hat package)
How to mitigate CVE-2021-32781
Install updates from vendor's website.
envoy - addressed in versions 1.16.5, 1.17.4, 1.18.4, 1.19.1
Istio - addressed in versions 1.9.8, 1.10.4, 1.11.1
servicemesh-proxy (Red Hat package) - addressed in versions 1.1.17-2.el8, 2.0.7-3.el8
servicemesh (Red Hat package) - addressed in versions 1.1.17-3.el8, 2.0.7-3.el8
Istio - addressed in versions 1.9.8, 1.10.4, 1.11.1
servicemesh-proxy (Red Hat package) - addressed in versions 1.1.17-2.el8, 2.0.7-3.el8
servicemesh (Red Hat package) - addressed in versions 1.1.17-3.el8, 2.0.7-3.el8