NULL pointer dereference in Envoyproxy Envoy
CVE-2021-43824
Envoy is an open source edge and service proxy, designed for cloud-native applications. In affected versions a crafted request crashes Envoy when a CONNECT request is sent to JWT filter configured with regex match. This provides a denial of service attack vector. The only workaround is to not use regex in the JWT filter. Users are advised to upgrade.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.011 (63.2th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 63rd percentile — 63.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000
Affected products
- Envoyproxy Envoy — versions >= 1.20.0, < 1.20.2, >= 1.19.0, < 1.19.3, < 1.18.6
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/envoyproxy/envoy/security/advisories/GHSA-vj5m-rch8-5r2p (Third Party Advisory, Issue Tracking)
- github.com/envoyproxy/envoy/commit/9371333230b1a6e1be2eccf4868771e11af6253a (Patch, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-43824?
- CVE-2021-43824 is a high-severity vulnerability in Envoyproxy Envoy, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2022-02-22.
- How severe is CVE-2021-43824?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2021-43824 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.