CVE-2023-20866
MEDIUMCVE-2023-20866 is a medium-severity (CVSS 6.5) Information Exposure vulnerability in vmware spring session. O3 Security detects and blocks CVE-2023-20866 exploitation at runtime via eBPF exploit-chain detection and L7 egress monitoring, even on unpatched systems.
In Spring Session version 3.0.0, the session id can be logged to the standard output stream. This vulnerability exposes sensitive information to those who have access to the application…
Description
In Spring Session version 3.0.0, the session id can be logged to the standard output stream. This vulnerability exposes sensitive information to those who have access to the application logs and can be used for session hijacking. Specifically, an application is vulnerable if it is using HeaderHttpSessionIdResolver.
Affected Products
spring sessionvmwareDetection & mitigation playbook
Vendor / applianceDetect
Inventory every vmware spring session 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.
Remediation status
No patch has shipped for CVE-2023-20866 yet — track the vmware spring session advisory for a fixed release and apply the workarounds below in the meantime.
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.
How O3 protects you
O3 detects and blocks CVE-2023-20866 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-2023-20866. 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-2023-20866 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2023-20866 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.