Fix (APAR): PH27157 Status: Fix Release: 8.5.5.18,8.5.5.17,8.5.5.16,8.5.5.15,8.5.5.14,8.5.5.13,8.5.5.12 Operating System: AIX,HP-UX,IBM i,Linux,Solaris,Windows,z/OS Supersedes Fixes: CMVC Defect: xxxxxx Byte size of APAR: 292491 Date: 2020-09-29 Abstract: WebSphere Application Server deserialization vulnerability (CVE-2020-4576 CVSS Score 5.3) Description/symptom of problem: PH27157 resolves the following problem: ERROR DESCRIPTION: WebSphere Application Server deserialization vulnerability (CVE-2020-4576 CVSS Score 5.3). LOCAL FIX: PROBLEM SUMMARY: WebSphere Application Server deserialization vulnerability (CVE-2020-4576 CVSS Score 5.3) PROBLEM CONCLUSION: Confidential for CVE-2020-4576. Directions to apply fix: Fix applies to Editions: Release 8.5 _X_ Application Server (Express or BASE) _X_ Network Deployment (ND) __ Liberty Core __ Edge Components _X_ Developer Install Fix to all WebSphere installations unless special instructions are included below. Special Instructions: None NOTE: The user must: * Logged in with the same authority level when unpacking a fix, fix pack or refresh pack. * Be at V1.4.3 or newer of the Installation Manager. Certain iFixes may require a newer version of the Installation Manager and the Installation Manager will inform you during the installation process if a newer version is required. The IBM Knowledge Center can provide details, if needed, on the use of the Installation Manager to apply the iFixes. http://publib.boulder.ibm.com/infocenter/install/v1r4/index.jsp. Shutdown WebSphere Application Server before applying the iFixes. Restart WebSphere Application Server after applying the iFixes. Directions to remove fix: The IBM Knowledge Center can provide details, if needed, on the use of the Installation Manager to remove the iFixes. http://publib.boulder.ibm.com/infocenter/install/v1r4/index.jsp. Shutdown WebSphere Application Server before removing the iFixes. Restart WebSphere Application Server after removing the iFixes. Directions to re-apply fix: 1) Shutdown WebSphere Application Server. 2) Follow the Fix instructions to apply the fix. 3) Restart WebSphere Application Server. Additional Information: