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CVE-2021-23017

HighCVSS 7.7 / 10
Published Jun 1, 2021·Last modified Apr 16, 2026
Affected Components(0)

No affected components available

Description

A security issue in nginx resolver was identified, which might allow an attacker who is able to forge UDP packets from the DNS server to cause 1-byte memory overwrite, resulting in worker process crash or potential other impact.

Risk Scores
Base Score
7.7

The vulnerability can be exploited over the network without needing physical access. It is difficult for an attacker to exploit this vulnerability and may require special conditions. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a high impact on the confidentiality of the information. There is a high impact on the integrity of the data. There is a low impact on the availability of the system.

Threat Intelligence
7.3

Exploitation activity has been observed. Apply available patches or mitigations urgently.

EPSS
53.46%

The exploit probability is high. The vulnerability is very likely to be exploited in the next 30 days.

Exploit
Proof of Concept

A proof of concept is available for this vulnerability (10 exploits found).

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