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Security Bulletin: Vulnerabilities in Curl affect PowerSC (CVE-2019-5435, CVE-2019-5436)

Security Bulletin


There are vulnerabilities in Curl that affect PowerSC.

Vulnerability Details

CVEID:   CVE-2019-5435
DESCRIPTION:   An integer overflow in curl's URL API results in a buffer overflow in libcurl 7.62.0 to and including 7.64.1.
CVSS Base score: 7.3
CVSS Temporal Score: See: for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L)

CVEID:   CVE-2019-5436
DESCRIPTION:   A heap buffer overflow in the TFTP receiving code allows for DoS or arbitrary code execution in libcurl versions 7.19.4 through 7.64.1.
CVSS Base score: 6.3
CVSS Temporal Score: See: for the current score.
CVSS Vector: (CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L)

Affected Products and Versions

Affected Product(s)Version(s)

The following fileset levels are vulnerable:

 Fileset Lower Level Upper Level


Note: To find out whether the affected PowerSC filesets are installed on your systems, refer to the lslpp command found in AIX user's guide.

Example: rpm -qa | grep curl



Fixes are available.

The fixes can be downloaded via ftp or http from:

The link above is a tar file containing this signed advisory, open source fix packages, and OpenSSL signatures for each package.

To extract the fixes from the tar file:

tar xvf curl_fix.tar

cd curl_fix

Verify you have retrieved the fixes intact:

The checksums below were generated using the "openssl dgst -sha256 [filename]" command as the following:

openssl dgst -sha256 filename KEY
56e394405836f1bdf7d188cef30adf5f6151fe594b39576dfbd953435e192569 ca-certificates-2016.10.7-2.aix6.1.ppc.rpm key_w_csum
5f01da544ae221c3f98ecd864782597b326f7838bb759cbb44b8366cad2eaeee curl-7.65.1-1.aix6.1.ppc.rpm key_w_csum
3ef01f3aea3e62ce402158ea892dfdb101d2c2f1c06256c6a245dc3126610bc0 db-6.2.32-2.aix6.1.ppc.rpm key_w_csum
7d1b39e1b8ab29a33edf9bb8fb589e071a6e0e06b69182f8a08776f497715f49 krb5-libs-1.16.1-2.aix6.1.ppc.rpm key_w_csum
dfd52c9b162b075abdaea908910ade3ee13d923e36a7e45cf6e1308ef5e62b52 libgcc-8.1.0-2.aix7.2.ppc.rpm key_w_csum

These sums should match exactly. The OpenSSL signatures in the tar file and on this advisory can also be used to verify the integrity of the fixes. If the sums or signatures cannot be confirmed, contact IBM Support.

openssl dgst -sha1 -verify <pubkey_file> -signature <advisory_file>.sig <advisory_file>

openssl dgst -sha1 -verify <pubkey_file> -signature <ifix_file>.sig <ifix_file>

Published advisory OpenSSL signature file location:…


IMPORTANT: If possible, it is recommended that a mksysb backup of the system be created. Verify it is both bootable and readable before proceeding.

To extract the fixes from the tar file:

tar xvf curl_fix.tar
cd curl_fix

To install a fix package:

rpm -ivh *.rpm
rpm -Uvh *.rpm

Interim fixes have had limited functional and regression testing but not the full regression testing that takes place for Service Packs; however, IBM does fully support them.

Workarounds and Mitigations


Get Notified about Future Security Bulletins



Change History

11 Nov 2019: Initial Publication

*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.


According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES ""AS IS"" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY.

Document Location


[{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SSNRQU","label":"PowerSC Express Edition"},"Component":"PowerSC","Platform":[{"code":"PF002","label":"AIX"}],"Version":"1.2","Edition":"All"}]

Document Information

Modified date:
20 December 2019