Security Bulletin: IBM InfoSphere Information Server is affected by a remote code execution vulnerability

Summary

A remote code execution vulnerability was addressed by IBM InfoSphere Information Server.

Vulnerability Details

CVEID:CVE-2020-4305
**DESCRIPTION:**IBM InfoSphere Information Server could allow a remote attacker to execute arbitrary code on the system, caused by the deserialization of untrusted data. By persuading a victim to visit a specially crafted Web site, an attacker could exploit this vulnerability to execute arbitrary code on the system.
CVSS Base score: 8.1
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/176677 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)

Affected Products and Versions

Remediation/Fixes

None

Workarounds and Mitigations

Installations using WebSphere Application Server Network Deployment

1. Change directory to <WAS Install location>/AppServer/profiles/<profile name>/config/cells/<cell name>/applications/isf-servlets.ear/deployments/isf-servlets/isf-servlets.war/WEB-INF
The default profile name is InfoSphere.
2. Open the web.xml file in an editor.
3. Within the security-constraint section
a. Locate lines that match the following url-pattern
<url-pattern>/javahttp/checked/</url-pattern>
b. Remove /checked to change the line to
<url-pattern>/javahttp/</url-pattern>
4. Add a new security-constraint after the existing security constraints:
<security-constraint> ** <web-resource-collection>** ** <web-resource-name>Public</web-resource-name>** ** <description>No Authorization resources</description>** ** <url-pattern>/javahttp/unchecked/*</url-pattern>** ** </web-resource-collection>** ** </security-constraint>**
5. Save the updated file.
6. Restart WAS.

Note: If you have a clustered environment, you can:
a. repeat the same steps for the deployment manager and all members of the cluster --or–
b. perform the steps on the deployment manager and run SyncNode (so web.xml on the nodes is updated)
After all are updated, restart the deployment manager and the cluster.

Installations using WebSphere Application Server****Liberty

1. Change directory to <Liberty install location>/wlp/usr/servers/iis/apps/isf
2. Extract isf-servlets.war using following command:
unzip isf-servlets.war
3. Open the isf-servlets/WEB-INF/web.xml file in an editor
4. Within the security-constraint section
a. Locate lines that match the following url-pattern
<url-pattern>/javahttp/checked/</url-pattern>
b. Remove /checked to change the line to
<url-pattern>/javahttp/</url-pattern>
5. Add a new security-constraint after the existing security constraints:
<security-constraint> ** <web-resource-collection>** ** <web-resource-name>Public</web-resource-name>** ** <description>No Authorization resources</description>** ** <url-pattern>/javahttp/unchecked/*</url-pattern>** ** </web-resource-collection>** ** </security-constraint>**
6. Save the updated file.
7. Repackage the war file:
a. Move the isf-servlets.war file to a backup location.
b. Create the new isf-servlets.war file
zip -r isf-servlets.war isf-servlets/
c. Verify that the new isf-servlets.war file is created in <Liberty install location>/wlp/usr/servers/iis/apps/isf
8. Remove the isf-servlets folder.
9. Restart Liberty WebSphere.