Bug 1780995 (CVE-2019-1551) - CVE-2019-1551 openssl: Integer overflow in RSAZ modular exponentiation on x86_64
Summary: CVE-2019-1551 openssl: Integer overflow in RSAZ modular exponentiation on x86_64
Keywords:
Status: NEW
Alias: CVE-2019-1551
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1781004 1781005 1781014 1781006 1781013 1781015
Blocks: 1780996
TreeView+ depends on / blocked
 
Reported: 2019-12-09 03:55 UTC by Huzaifa S. Sidhpurwala
Modified: 2020-01-30 08:54 UTC (History)
43 users (show)

Fixed In Version:
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Doc Text:
An integer overflow was found in the x64_64 Montgomery squaring procedure used in exponentiation with 512-bit moduli. As per upstream: * No EC algorithms are affected. * Attacks against 2-prime RSA1024, 3-prime RSA1536, and DSA1024 as a result of this defect would be very difficult to perform and are not believed likely. * Attacks against DH512 are considered just feasible. However, for an attack the target would have to re-use the DH512 private key, which is not recommended anyway. * Also applications directly using the low level API BN_mod_exp may be affected if they use BN_FLG_CONSTTIME
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Description Huzaifa S. Sidhpurwala 2019-12-09 03:55:08 UTC
As per openssl upstream advisory:

There is an overflow bug in the x64_64 Montgomery squaring procedure used in exponentiation with 512-bit moduli. No EC algorithms are affected. Analysis suggests that attacks against 2-prime RSA1024, 3-prime RSA1536, and DSA1024 as a result of this defect would be very difficult to perform and are not believed likely. Attacks against DH512 are considered just feasible. However, for an attack the target would have to re-use the DH512 private key, which is not recommended anyway. Also applications directly using the low level API BN_mod_exp may be affected if they use BN_FLG_CONSTTIME.

OpenSSL versions 1.1.1 and 1.0.2 are affected by this issue. However due to the low severity of this issue we are not creating new releases at this time. The 1.1.1 mitigation for this issue can be found in commit 419102400. The 1.0.2 mitigation for this issue can be found in commit f1c5eea8a.

Comment 1 Huzaifa S. Sidhpurwala 2019-12-09 03:57:26 UTC
External References:

https://www.openssl.org/news/secadv/20191206.txt
https://github.com/openssl/openssl/pull/10575

Comment 3 Huzaifa S. Sidhpurwala 2019-12-09 04:53:30 UTC
Created mingw-openssl tracking bugs for this issue:

Affects: epel-7 [bug 1781006]
Affects: fedora-all [bug 1781005]


Created openssl tracking bugs for this issue:

Affects: fedora-all [bug 1781004]

Comment 4 Huzaifa S. Sidhpurwala 2019-12-09 05:29:20 UTC
Statement:

Accelerated modular exponentiation for Intel processors (RSAZ) was introduced in openssl-1.0.2, therefore older versions of OpenSSL are not affected by this flaw.

Comment 6 Ted (Jong Seok) Won 2019-12-11 01:21:11 UTC
This vulnerability is out of security support scope for the following products:
 * Red Hat JBoss Enterprise Application Platform 6
 * Red Hat JBoss Enterprise Web Server 2

Please refer to https://access.redhat.com/support/policy/updates/jboss_notes for more details.

Comment 7 Laurie Morse 2020-01-23 19:24:51 UTC
We use Red Hat Enterprise Linux 8 (RHEL8) specifically we use container images ubi8/ubi-minimal.  When we install openssl we get version 1.1.1c and apparently the fix is in 1.1.1e.
We also use Red Hat Enterprise Linux 7 (RHEL7) as container image ubi7/ubi-minimal.  When we install openssl we get version 1.0.2k and the fix is in 1.0.2u.

It is stated that RHEL8 is "affected" by CVE-2019-1551 - https://access.redhat.com/security/cve/cve-2019-1551
It is also stated that RHEL7 is "Will not fix".

Will RHEL8 be fixed by this bugzilla ticket?  When can we expect this fix?  Do I need to open another bugzilla ticket?
Will RHEL7 never be fixed?

Comment 9 Tomas Mraz 2020-01-30 08:54:04 UTC
RHEL-7:

512 bit DH is already disabled. As this bug is about leakage of the private key to the attacker, it should be fully sufficient to just not use 1024 bit RSA keys or 1024 bit DSA keys. These keys are not secure enough anyway. 3-prime RSA keys are not supported on RHEL-7.

RHEL-8:

The DEFAULT crypto policy already disables all these key sizes.


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