CVE-2021-28683 Null dereference in n/a

What is CVE-2021-28683?

CVE-2021-28683 is a high-severity vulnerability in Envoyproxy Envoy, published on 20 May 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

An issue was discovered in Envoy through 1.71.1. There is a remotely exploitable NULL pointer dereference and crash in TLS when an unknown TLS alert code is received.

Weakness: CWE-476

Which versions are affected by CVE-2021-28683?

1 open source package ship an affected version, including envoy. It affects 1 product.

Products include Envoyproxy Envoy.

How do I fix CVE-2021-28683?

Upgrade envoy to a fixed version for your release line: 1.16.3 or 1.17.2.

Is CVE-2021-28683 being exploited?

There is no known exploitation of CVE-2021-28683 in the wild and no public exploit code.

Other vulnerabilities in Envoyproxy Envoy

• CVE-2022-29226 Trivial authentication bypass in Envoy Critical 10.0
• CVE-2019-18801 Memory corruption in n/a Critical 9.8
• CVE-2019-18802 Security feature bypass in n/a Critical 9.8
• CVE-2020-35470 Information disclosure in n/a High 8.8
• CVE-2024-23324 Envoy ext auth can be bypassed when Proxy protocol filter sets invalid UTF-8 metadata High 8.6

All Envoyproxy Envoy vulnerabilities

Sources

• CVE record
• NVD
• OSV
• How this page is made

Also known as BIT-envoy-2021-28683.