CVE-2021-31474
CRITICALCVE-2021-31474 is a critical-severity (CVSS 9.8) Deserialization of Untrusted Data vulnerability in solarwinds network performance monitor. EPSS puts its 30-day exploitation probability at 94.4% (100th percentile). O3 Security detects and blocks CVE-2021-31474 exploitation at runtime via eBPF exploit-chain detection and L7 egress monitoring, even on unpatched systems.
This vulnerability allows remote attackers to execute arbitrary code on affected installations of SolarWinds Network Performance Monitor 2020.2.1. Authentication is not required to…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Description
This vulnerability allows remote attackers to execute arbitrary code on affected installations of SolarWinds Network Performance Monitor 2020.2.1. Authentication is not required to exploit this vulnerability. The specific flaw exists within the SolarWinds.Serialization library. The issue results from the lack of proper validation of user-supplied data, which can result in deserialization of untrusted data. An attacker can leverage this vulnerability to execute code in the context of SYSTEM. Was ZDI-CAN-12213.
Affected Products
network performance monitorsolarwindsDetection & mitigation playbook
Vendor / applianceDetect
Inventory every solarwinds network performance monitor 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 remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Fix
Apply the solarwinds network performance monitor security patch or hotfix for CVE-2021-31474 on the affected version, following the vendor advisory for your exact build.
Workarounds
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.
How O3 protects you
O3 detects and blocks CVE-2021-31474 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-2021-31474. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2021-31474 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2021-31474 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.