CVE-2021-28683
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.
02 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.
03 Exploitation and scoring
- Exploitation
- Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
- SSVC decision
- Not assessed by CISA
- EPSS probability
- 1.68% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 76.5% of scored records. A rank, not a probability.
- NVD base score
- 7.5 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVD analysis status
- Modified. NVD last modified this record on 2026-06-17.
- Red Hat severity
- Important. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2021-05-20 16:34Z5 YR AGO
- Last updated
- 2024-08-03 21:47Z2 YR AGO
- Reserved
- 2021-03-18
- Assigning CNA
- mitre
- Record state
- PUBLISHED
- Severity
- Not rated by the issuing CNA
- CNA CVSS vector
- Not published by the issuing CNA
- Weaknesses
- CWE-476NULL Pointer DereferenceBase
- Data version
- 5.1
- Document digest
- eb4672d0a5c35c99795489bafe4cc1112a494ae7df00c6dbaf09182f02fd048c
05 Affected products
06 References
- github.comhttps://github.com/envoyproxy/envoy/releases
- blog.envoyproxy.iohttps://blog.envoyproxy.io
- github.comhttps://github.com/envoyproxy/envoy/security/advisories/GHSA-r22g-5f3x-xjgg
07 Fixed in
Arch Linux
- istio Fixed in 1.10.0-1
Source: Arch Linux Security Tracker, the Arch Linux security team. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.