Security Bulletin: A vulnerability has been identified in IBM Spectrum Scale where an unprivileged user could execute commands as root ( CVE-2020-4273)

Summary

A security vulnerability has been identified in all levels of IBM Spectrum Scale that could allow underprivileged attacker to execute commands as root. A fix for this vulnerability is available.

Vulnerability Details

CVEID:CVE-2020-4273
**DESCRIPTION:**IBM Spectrum Scale could allow a local unprivileged attacker with intimate knowledge of the enviornment to execute commands as root using specially crafted input.
CVSS Base score: 7.4
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/175977 for the current score.
CVSS Vector: (CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)

Affected Products and Versions

Remediation/Fixes

For IBM Spectrum Scale V5.0.0.0 through 5.0.4.2, apply V5.0.4.3 available from FixCentral at:

https://www.ibm.com/support/fixcentral/swg/selectFixes?parent=Software%20defined%20storage&product=ibm/StorageSoftware/IBM+Spectrum+Scale&release=5.0.4&platform=All&function=all

For IBM Spectrum Scale V4.2.0.0 through V4.2.3.20, apply V4.2.3.21 available from FixCentral at:

https://www.ibm.com/support/fixcentral/swg/selectFixes?parent=Software%20defined%20storage&product=ibm/StorageSoftware/IBM+Spectrum+Scale&release=4.2.3&platform=All&function=all

If you cannot apply the latest level of service, contact IBM Service for an efix:

- For IBM Spectrum Scale V5.0.0.0 through V5.0.4.2, reference APAR IJ23438

- For IBM Spectrum Scale V4.2.0.0 through V4.2.3.20, reference APAR IJ23426

Workarounds and Mitigations

Until the fixes can be applied, a workaround is to remove the setuid from the files in the /usr/lpp/mmfs/bin directory. Determine the set of files with setuid bit by running

ls -l /usr/lpp/mmfs/bin | grep r-s

Then reset the setuid bit for each such file by issuing this command on each file

chmod u-sfile

Once the workaround is applied, a number of commands may no longer work when not invoked by unprivileged users, including:

mmchfileset mmcrsnapshot mmdelsnapshot mmdf mmedquota mmgetacl mmlsdisk mmlsfileset mmlsfs mmlsmgr mmlspolicy mmlspool mmlsquota mmlssnapshot mmputacl mmsnapdir