bash: Increased privileges - Existing account

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                         ZMCIRT Vulnerability Bulletin

                             ZMC-2021.05.19.0800
                      bash: Increased privileges - Existing account
                               19th May 2021

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Product:           bash
Publisher:         Red Hat
Operating System:  Red Hat
Impact/Access:     Increased Privileges -- Existing Account
Resolution:        Patch/Upgrade
CVE Names:         CVE-2019-18276  

Reference:         ESB-2020.0317

Original Bulletin: 
   https://access.redhat.com/errata/RHSA-2021:1679


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                   Red Hat Security Advisory

Synopsis:          Low: bash security and bug fix update
Advisory ID:       RHSA-2021:1679-01
Product:           Red Hat Enterprise Linux
Advisory URL:      https://access.redhat.com/errata/RHSA-2021:1679
Issue date:        2021-05-18
CVE Names:         CVE-2019-18276 
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1. Summary:

An update for bash is now available for Red Hat Enterprise Linux 8.

Red Hat Product Security has rated this update as having a security impact
of Low. A Common Vulnerability Scoring System (CVSS) base score, which
gives a detailed severity rating, is available for each vulnerability from
the CVE link(s) in the References section.

2. Relevant releases/architectures:

Red Hat Enterprise Linux BaseOS (v. 8) - aarch64, ppc64le, s390x, x86_64

3. Description:

The bash packages provide Bash (Bourne-again shell), which is the default
shell for Red Hat Enterprise Linux.

Security Fix(es):

* bash: when effective UID is not equal to its real UID the saved UID is
not dropped (CVE-2019-18276)

For more details about the security issue(s), including the impact, a CVSS
score, acknowledgments, and other related information, refer to the CVE
page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the Red Hat
Enterprise Linux 8.4 Release Notes linked from the References section.

4. Solution:

For details on how to apply this update, which includes the changes
described in this advisory, refer to:

https://access.redhat.com/articles/11258

5. Bugs fixed (https://bugzilla.redhat.com/):

1778309 - CVE-2019-18276 bash: when effective UID is not equal to its real UID the saved UID is not dropped
1890888 - Took long time to return when bash -c 'exit 2 & wait $!' run in the big size LimitNPROC values

6. Package List:

Red Hat Enterprise Linux BaseOS (v. 8):

Source:
bash-4.4.19-14.el8.src.rpm

aarch64:
bash-4.4.19-14.el8.aarch64.rpm
bash-debuginfo-4.4.19-14.el8.aarch64.rpm
bash-debugsource-4.4.19-14.el8.aarch64.rpm
bash-doc-4.4.19-14.el8.aarch64.rpm

ppc64le:
bash-4.4.19-14.el8.ppc64le.rpm
bash-debuginfo-4.4.19-14.el8.ppc64le.rpm
bash-debugsource-4.4.19-14.el8.ppc64le.rpm
bash-doc-4.4.19-14.el8.ppc64le.rpm

s390x:
bash-4.4.19-14.el8.s390x.rpm
bash-debuginfo-4.4.19-14.el8.s390x.rpm
bash-debugsource-4.4.19-14.el8.s390x.rpm
bash-doc-4.4.19-14.el8.s390x.rpm

x86_64:
bash-4.4.19-14.el8.x86_64.rpm
bash-debuginfo-4.4.19-14.el8.x86_64.rpm
bash-debugsource-4.4.19-14.el8.x86_64.rpm
bash-doc-4.4.19-14.el8.x86_64.rpm

These packages are GPG signed by Red Hat for security.  Our key and
details on how to verify the signature are available from
https://access.redhat.com/security/team/key/

7. References:

https://access.redhat.com/security/cve/CVE-2019-18276
https://access.redhat.com/security/updates/classification/#low
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/8.4_release_notes/



 
ZMCIRT has made every effort to ensure that the information contained
in this document is accurate.  However, the decision to use the information
described is the responsibility of each user or organisation. The decision to
follow or act on information or advice contained in this security bulletin is
the responsibility of each user or organisation, and should be considered in
accordance with your organisation's site policies and procedures. ZMCERT
takes no responsibility for consequences which may arise from following or
acting on information or advice contained in this security bulletin.

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