Thursday Jul 30, 2015

CVSS Version 3.0 Announced

Hello, this is Darius Wiles.

Version 3.0 of the Common Vulnerability Scoring System (CVSS) has been announced by the Forum of Incident Response and Security Teams (FIRST). Although there have been no high-level changes to the standard since the Preview 2 release which I discussed in a previous blog post, there have been a lot of improvements to the documentation.

Soon, Oracle will be using CVSS v3.0 to report CVSS Base scores in its security advisories. In order to facilitate this transition, Oracle plans to release two sets of risk matrices, both CVSS v2 and v3.0, in the first Critical Patch Update (Oracle’s security advisories) to provide CVSS version 3.0 Base scores. Subsequent Critical Patch Updates will only list CVSS version 3.0 scores.

While Oracle expects most vulnerabilities to have similar v2 and v3.0 Base Scores, certain types of vulnerabilities will experience a greater scoring difference. The CVSS v3.0 documentation includes a list of examples of public vulnerabilities scored using both v2 and v3.0, and this gives an insight into these scoring differences. Let’s now look at a couple of reasons for these differences.

The v3.0 standard provides a more precise assessment of risk because it considers more factors than the v2 standard. For example, the important impact of most cross-site scripting (XSS) vulnerabilities is that a victim's browser runs malicious code. v2 does not have a way to capture the change in impact from the vulnerable web server to the impacted browser; basically v2 just considers the impact to the former. In v3.0, the Scope metric allows us to score the impact to the browser, which in v3.0 terminology is the impacted component. v2 scores XSS as "no impact to confidentiality or availability, and partial impact to integrity", but in v3.0 we are free to score impacts to better fit each vulnerability. For example, a typical XSS vulnerability, CVE-2013-1937 is scored with a v2 Base Score of 4.3 and a v3.0 Base Score of 6.1. Most XSS vulnerabilities will experience a similar CVSS Base Score increase.

Until now, Oracle has used a proprietary Partial+ metric value for v2 impacts when a vulnerability "affects a wide range of resources, e.g., all database tables, or compromises an entire application or subsystem". We felt this extra information was useful because v2 always scores vulnerabilities relative to the "target host", but in cases where a host's main purpose is to run a single application, Oracle felt that a total compromise of that application warrants more than Partial. In v3.0, impacts are scored relative to the vulnerable component (assuming no scope change), so a total compromise of an application now leads to High impacts. Therefore, most Oracle vulnerabilities scored with Partial+ impacts under v2 are likely to be rated with High impacts and therefore more precise v3.0 Base scores. For example, CVE-2015-1098 has a v2 Base score of 6.8 and a v3.0 Base score of 7.8. This is a good indication of the differences we are likely to see. Refer to the CVSS v3.0 list of examples for more details on score this vulnerability.

Overall, Oracle expects v3.0 Base scores to be higher than v2, but bear in mind that v2 scores are always relative to the "target host", whereas v3.0 scores are relative to the vulnerable component, or the impacted component if there is a scope change. In other words, CVSS v3.0 will provide a better indication of the relative severity of vulnerabilities because it better reflects the true impact of the vulnerability being rated in software components such as database servers or middleware.


For More Information

The CVSS v3.0 documents are located on FIRST's web site at http://www.first.org/cvss/

Oracle's use of CVSS [version 2], including a fuller explanation of Partial+ is located at http://www.oracle.com/technetwork/topics/security/cvssscoringsystem-091884.html

My previous blog post on CVSS v3.0 preview is located at https://blogs.oracle.com/security/entry/cvss_version_3_0_preview

Eric Maurice's blog post on Oracle's use of CVSS v2 is located at https://blogs.oracle.com/security/entry/understanding_the_common_vulne_2

Friday Aug 10, 2012

Security Alert CVE-2012-3132 Released

Hi, this is Eric Maurice.

Oracle today released Security Alert CVE-2012-3132 to address a vulnerability affecting the Oracle Database Server, which was publicly disclosed at BlackHat 2012.  With a CVSS Base Score of 6.5, this vulnerability involves the ‘INDEXTYPE CTXSYS.CONTEXT’, and if successfully exploited, can allow a malicious attacker to gain ‘SYS’ privileges.  This vulnerability does not affect 11gR2 databases which have applied the July 2012 Critical Patch Update.  Note that this vulnerability is not remotely exploitable without authentication, in other words, the attacker needs to a have credentials and specific privileges, including the ‘Create Table’ privilege, in order to create the exploit conditions.  Oracle recommends that organizations apply this Security Alert as soon as possible because the technical details of this vulnerability have been very widely disclosed and one can easily find sample exploit code over the Internet.

As much as possible, it is important that organizations use the most current product versions available to them.  As stated in each Critical Patch Update and Security Alert Advisory, Oracle does not generally test for the presence of the vulnerabilities fixed through the Critical Patch Update and Security Alert programs in releases of affected product lines that are no longer supported.  However, it is likely that these vulnerabilities exist in previously released, but no longer supported releases of the affected products.  In a previous blog entry, I discussed Oracle’s security fixing policies, and recommended that customers remain on current releases in order to take advantage of Oracle’s ongoing security assurance effort.  This Security Alert, along with all recently released Critical Patch Updates, is an example of the importance of keeping up with newer and actively supported releases.  Customers on unsupported versions, unless they have purchased Extended Support under the Lifetime Support Policy, will not receive a permanent fix for the release they are running. 

It is unfortunate when the technical details of a security vulnerability are disclosed before a fix could be made available, especially when the disruption resulting from having to deal with an unplanned patch, and the amount of time required by customers to apply the patch, may yield less of a security posture improvement than other security efforts, such as ongoing hardening and auditing. 

For more information:

The Security Alerts and Critical Patch Updates page is located at http://www.oracle.com/technetwork/topics/security/alerts-086861.html

The Advisory for Security Alert CVE-2012-3132 is located at www.oracle.com/technetwork/topics/security/alert-cve-2012-3132-1721017.html

The Oracle Software Security Assurance web site is located at http://www.oracle.com/us/support/assurance/index.html

The blog entry “Take Advantage of Oracle's Ongoing Assurance Effort!” is located at https://blogs.oracle.com/security/entry/take_advantage_of_oracles_ongo

The blog entry “Keeping Up With Newer Releases is Good Security Practice” is located at https://blogs.oracle.com/security/entry/keeping_up_with_newer_releases

 

 

Monday Apr 30, 2012

Security Alert for CVE-2012-1675 Released

Hi, this is Eric Maurice.

Oracle just released Security Alert CVE-2012-1675 to address the “TNS Listener Poison Attack” in the Oracle Database.  With a CVSS Base Score of 7.5, this vulnerability is remotely exploitable without authentication, and if successfully exploited, can result in a full compromise of the targeted Database.

In the April 2012 Critical Patch Update, Oracle provided Security-in-Depth recognition to Joxean Koret.  As stated in the Critical Patch Update advisories, “People are recognized for Security-In-Depth contributions if they provide information, observations or suggestions pertaining to security vulnerability issues that result in significant modification of Oracle code or documentation in future releases, but are not of such a critical nature that they are distributed in Critical Patch Updates.

As stated in previous blog entries, Oracle fixes vulnerability first in the main code line, and then tries to backport fixes through the Critical Patch Update program for exploitable vulnerabilities that were externally reported.  In certain instances, such backporting is very difficult or impossible because of the amount of code change required, or because the fix would create significant regressions, or because there is no reasonable way to automate the application of the fix (for example when user interaction is required to change configuration parameters). 

Shortly after the release of the Critical Patch Update, mistakenly assuming that the issue had been backported through the CPU, Joxean Koret, the initial reporter of this vulnerability, fully disclosed its details, initially stating that it had been fixed by Oracle, then after realizing that it had not been fixed in current releases, reported the vulnerability as a “0-day.”  

As a result of this disclosure, Oracle has issued Security Alert CVE-2012-1675 to provide customers with a number of technical measures to provide effective defense against this vulnerability in all deployment scenarios.

Customers on single-node configurations (i.e., non Real Application Cluster (RAC) customers) should refer to the My Oracle Support Note titled “Using Class of Secure Transport (COST) to Restrict Instance Registration” (Doc ID 1453883.1) to limit registration to the local node and the IPC protocol through the COST (Class Of Secure Transport) feature in the listener.

RAC and Exadata customers should refer to the My Oracle Support Note “Using Class of Secure Transport (COST) to Restrict Instance Registration in Oracle RAC” (Doc ID 1340831.1) to implement similar COST restrictions. 

Note that implementing COST restrictions in RAC environments require the use of SSL/TLS encryption.  Such network encryption features were previously only available to customers who were licensed for Oracle Advanced Security.  However, RAC customers who were previously not licensed for Oracle Advanced Security need not be concerned about a licensing restriction as Oracle has updated its licensing to allow these customers the use of these features (namely SSL and TLS) to protect themselves against vulnerability CVE-2012-1675.  In other words, Oracle has added Oracle Advanced Security SSL/TLS to the Enterprise Edition Real Application Clusters (Oracle RAC) and RAC One Node options, and added Oracle Advanced Security SSL/TLS to the Oracle Database Standard Edition license when used with the Real Application Clusters.

Considering that the technical details of vulnerability CVE-2012-1675 have now widely been distributed, Oracle highly recommends that customers make the configuration changes documented in the above mentioned My Oracle Support Notes as soon as possible.  Customers should also feel free to contact Oracle Support if they have questions or concerns.

For More Information:

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