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CVE-2022-2835

MEDIUM

CVE-2022-2835 is a medium-severity (CVSS 4.4) CWE-923 vulnerability in coredns.io coredns. O3 Security detects and blocks CVE-2022-2835 exploitation at runtime via eBPF exploit-chain detection and L7 egress monitoring, even on unpatched systems.

A flaw was found in coreDNS. This flaw allows a malicious user to reroute internal calls to some internal services that were accessed by the FQDN in a format of <service>.<namespace>.svc.

Published
Mar 3, 2023
Updated
Jun 17, 2026
Affected
0 pkgs
Patched
None yet
Exploits
None indexed

Description

A flaw was found in coreDNS. This flaw allows a malicious user to reroute internal calls to some internal services that were accessed by the FQDN in a format of <service>.<namespace>.svc.

Affected Products

1 product · 1 configurations
Application
corednscoredns.io
all

Detection & mitigation playbook

Vendor / appliance
  1. Detect

    Inventory every coredns.io coredns deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.

  2. Remediation status

    No patch has shipped for CVE-2022-2835 yet — track the coredns.io coredns advisory for a fixed release and apply the workarounds below in the meantime.

  3. Mitigate without a patch

    Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.

  4. How O3 protects you

    O3 detects and blocks CVE-2022-2835 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Tailored to CVE-2022-2835. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

A flaw was found in coreDNS. This flaw allows a malicious user to reroute internal calls to some internal services that were accessed by the FQDN in a format of <service>.<namespace>.svc.
O3 Security · Runtime Protection

Is CVE-2022-2835 being exploited in your environment?

O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2022-2835 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.