Security
Keeping administrators up to date
Keeping up with distribution security updates is typically straightforward, but finding out about vulnerable packages before they have been patched can be rather harder. There is generally a lag between the report of a vulnerability and the availability of an updated package. In that window, there might well be steps that administrators could take to mitigate or work around the problem, but they can only do so if they are aware of the problem. In our recent article that looked at distribution response to the MoinMoin and Rails vulnerabilities, there was a suggestion that distributions could do more to help notify administrators of known-but-unpatched security holes. As it turns out, a comment on that article led us to one example of just such an early warning system.
The tool in question is debsecan (Debian security analyzer), which helps Debian administrators keep up with the vulnerabilities reported against the packages they have installed. By consulting the Debian security bug tracker, debsecan gets information about entries in the CVE (Common Vulnerabilities and Exposures) and National Vulnerability Database lists that it can correlate with the packages installed on the system. It runs hourly by default, and can email interested parties with its results once per day.
Debsecan was written by Florian Weimer, starting back at the end of 2005; at this point, it is fairly stable and has remained largely unchanged since mid-2010. The program is less than 1500 lines of Python, with just a few dependencies (e.g., libapt-pkg bindings). That dependency and the reliance on the bug tracker make it quite Debian-specific, of course, but the idea behind it is more widely applicable.
Obviously, debsecan depends on the information in the security bug tracker being kept up to date. That is handled by the Debian security team, though volunteers are welcome. The team has put together an introduction to the security bug tracker that describes the process it uses to track security problems for Debian. Other distributions also track security problems, of course, but tools like debsecan that specifically look for problems that have not yet been patched are not common.
Ubuntu carries debsecan in its repositories, but it is too
Debian-specific to be directly useful on Ubuntu and, so far, efforts
to Ubuntu-ize it have not gone anywhere.
At this point, the package is targeted for removal from Ubuntu, because it
"conveys information that is just plain wrong
" for Ubuntu.
For other distributions, package managers (e.g., yum,
zypper) will list available updates, and can often filter that list based
on security updates, but don't list unpatched packages.
It is, of course, best if a distribution can keep up with the security problems in its packages, but that can be difficult at times. Like with the recent MoinMoin and Rails vulnerabilities, though, there are often ways to mitigate a particular problem—if the administrator is alerted. Even if there is no workaround available, an administrator could choose to completely disable the affected package (or install a patched version from source) while awaiting a distribution update. There is some similarity with the arguments in favor of "full disclosure" here: essentially, the more each individual knows about the vulnerabilities of their software, the more options for handling the problem they have. Without that information, those options are severely limited—in fact, largely non-existent.
One could imagine a cross-distribution project that gathered the same kind of information as the Debian security bug tracker, but in a more distribution-independent fashion. Each distribution could have a tool that processed that data, correlated it to its package names and versions, and then reported on what it found. It could even potentially be extended to help track software that is installed from source.
Keeping up with security updates for source installations can definitely be a problem area. While many larger projects have advisory announcement mailing lists, there are plenty of smaller projects that aren't quite as formal. That means that there are multiple sources of security advisories that an administrator needs to keep track of. By maintaining some kind of list of locally installed packages, coupled with a central storehouse of vulnerabilities, a tool like debsecan could also be used to provide alerts to security holes in local source-installed packages as well.
There are plenty of reasons that administrators will install from source—new features and bug fixes, compatibility with other packages, and so on. Those packages are often things like fast-moving web frameworks or applications that have high risk profiles. A tool that helped administrators keep up with the security issues in source packages, while also integrating the distribution package vulnerabilities and updates, would be a real boon for Linux.
Brief items
Security quotes of the week
In the end, the old gods of information scarcity and control will indeed die, and more open models will win the future.
New vulnerabilities
389-ds-base: ACL restriction bypass
Package(s): | 389-ds-base | CVE #(s): | CVE-2012-4450 | ||||||||||||||||||||
Created: | January 15, 2013 | Updated: | March 11, 2013 | ||||||||||||||||||||
Description: | From the CVE entry:
389 Directory Server 1.2.10 does not properly update the ACL when a DN entry is moved by a modrdn operation, which allows remote authenticated users with certain permissions to bypass ACL restrictions and access the DN entry. | ||||||||||||||||||||||
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asterisk: denial of service
Package(s): | asterisk | CVE #(s): | CVE-2012-5976 CVE-2012-5977 | ||||||||||||||||||||||||||||
Created: | January 14, 2013 | Updated: | January 30, 2013 | ||||||||||||||||||||||||||||
Description: | From the CVE entries:
Multiple stack consumption vulnerabilities in Asterisk Open Source 1.8.x before 1.8.19.1, 10.x before 10.11.1, and 11.x before 11.1.2; Certified Asterisk 1.8.11 before 1.8.11-cert10; and Asterisk Digiumphones 10.x-digiumphones before 10.11.1-digiumphones allow remote attackers to cause a denial of service (daemon crash) via TCP data using the (1) SIP, (2) HTTP, or (3) XMPP protocol. (CVE-2012-5976) Asterisk Open Source 1.8.x before 1.8.19.1, 10.x before 10.11.1, and 11.x before 11.1.2; Certified Asterisk 1.8.11 before 1.8.11-cert10; and Asterisk Digiumphones 10.x-digiumphones before 10.11.1-digiumphones, when anonymous calls are enabled, allow remote attackers to cause a denial of service (resource consumption) by making anonymous calls from multiple sources and consequently adding many entries to the device state cache. (CVE-2012-5977) | ||||||||||||||||||||||||||||||
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autofs: denial of service
Package(s): | autofs | CVE #(s): | CVE-2012-2697 | ||||||||||||
Created: | January 14, 2013 | Updated: | January 17, 2013 | ||||||||||||
Description: | From the Red Hat advisory:
A bug fix included in RHBA-2012:0264 introduced a denial of service flaw in autofs. When using autofs with LDAP, a local user could use this flaw to crash autofs, preventing future mount requests from being processed until the autofs service was restarted. | ||||||||||||||
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conga: leaks authentication credentials
Package(s): | conga | CVE #(s): | CVE-2012-3359 | ||||||||||||
Created: | January 14, 2013 | Updated: | January 17, 2013 | ||||||||||||
Description: | From the Red Hat advisory:
It was discovered that luci stored usernames and passwords in session cookies. This issue prevented the session inactivity timeout feature from working correctly, and allowed attackers able to get access to a session cookie to obtain the victim's authentication credentials. | ||||||||||||||
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drupal7-context: information disclosure
Package(s): | drupal7-context | CVE #(s): | CVE-2012-5655 | ||||||||||||||||
Created: | January 14, 2013 | Updated: | January 21, 2013 | ||||||||||||||||
Description: | From the CVE entry:
The Context module 6.x-3.x before 6.x-3.1 and 7.x-3.x before 7.x-3.0-beta6 for Drupal does not properly restrict access to block content, which allows remote attackers to obtain sensitive information via a crafted request. | ||||||||||||||||||
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freeciv: denial of service
Package(s): | freeciv | CVE #(s): | CVE-2012-6083 | ||||
Created: | January 15, 2013 | Updated: | January 16, 2013 | ||||
Description: | From the Mageia advisory:
Malformed network packets could cause denial of service (memory exhaustion or CPU-bound loop) in Freeciv before 2.3.3 See the Freeciv announcement for more details. | ||||||
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java: multiple vulnerabilities
Package(s): | java-1.7.0-oracle | CVE #(s): | CVE-2012-3174 CVE-2013-0422 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Created: | January 15, 2013 | Updated: | January 25, 2013 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Description: | From the CVE entries:
Unspecified vulnerability in Oracle Java 7 before Update 11 allows remote attackers to affect confidentiality, integrity, and availability via unknown vectors, a different vulnerability than CVE-2013-0422. NOTE: some parties have mapped CVE-2012-3174 to an issue involving recursive use of the Reflection API, but that issue is already covered as part of CVE-2013-0422. This identifier is for a different vulnerability whose details are not public as of 20130114. (CVE-2012-3174) Multiple vulnerabilities in Oracle Java 7 before Update 11 allow remote attackers to execute arbitrary code by (1) using the public getMBeanInstantiator method in the JmxMBeanServer class to obtain a reference to a private MBeanInstantiator object, then retrieving arbitrary Class references using the findClass method, and (2) using the Reflection API with recursion in a way that bypasses a security check by the java.lang.invoke.MethodHandles.Lookup.checkSecurityManager method due to the inability of the sun.reflect.Reflection.getCallerClass method to skip frames related to the new reflection API, as exploited in the wild in January 2013, as demonstrated by Blackhole and Nuclear Pack, and a different vulnerability than CVE-2012-4681 and CVE-2012-3174. NOTE: some parties have mapped the recursive Reflection API issue to CVE-2012-3174, but CVE-2012-3174 is for a different vulnerability whose details are not public as of 20130114. CVE-2013-0422 covers both the JMX/MBean and Reflection API issues. NOTE: it was originally reported that Java 6 was also vulnerable, but the reporter has retracted this claim, stating that Java 6 is not exploitable because the relevant code is called in a way that does not bypass security checks. NOTE: as of 20130114, a reliable third party has claimed that the findClass/MBeanInstantiator vector was not fixed in Oracle Java 7 Update 11. If there is still a vulnerable condition, then a separate CVE identifier might be created for the unfixed issue. (CVE-2013-0422) See the Oracle Security Alert for additional information. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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kde-filesystem: insecure build flags
Package(s): | kde-filesystem | CVE #(s): | |||||
Created: | January 14, 2013 | Updated: | January 16, 2013 | ||||
Description: | From the Red Hat bugzilla:
Sync FFLAGS and LDFLAGS in the %cmake_kde4 macro with redhat-rpm-config | ||||||
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kexec-tools: executable stack
Package(s): | kexec-tools | CVE #(s): | |||||
Created: | January 15, 2013 | Updated: | January 16, 2013 | ||||
Description: | Fedora fixed an executable stack issue for ppc32 in kexec-tools 2.0.3-64. | ||||||
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mozilla: cross-site scripting
Package(s): | iceape, thunderbird, seamonkey, firefox | CVE #(s): | CVE-2013-0751 | ||||||||||||||||||||||||||||||||
Created: | January 15, 2013 | Updated: | February 18, 2013 | ||||||||||||||||||||||||||||||||
Description: | From the CVE entry:
Mozilla Firefox before 18.0 on Android and SeaMonkey before 2.15 do not restrict a touch event to a single IFRAME element, which allows remote attackers to obtain sensitive information or possibly conduct cross-site scripting (XSS) attacks via a crafted HTML document. | ||||||||||||||||||||||||||||||||||
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mysql: authentication bypass
Package(s): | mysql | CVE #(s): | CVE-2012-4452 | ||||||||||||
Created: | January 14, 2013 | Updated: | January 17, 2013 | ||||||||||||
Description: | From the CVE entry:
MySQL 5.0.88, and possibly other versions and platforms, allows local users to bypass certain privilege checks by calling CREATE TABLE on a MyISAM table with modified (1) DATA DIRECTORY or (2) INDEX DIRECTORY arguments that are originally associated with pathnames without symlinks, and that can point to tables created at a future time at which a pathname is modified to contain a symlink to a subdirectory of the MySQL data home directory, related to incorrect calculation of the mysql_unpacked_real_data_home value. NOTE: this vulnerability exists because of a CVE-2009-4030 regression, which was not omitted in other packages and versions such as MySQL 5.0.95 in Red Hat Enterprise Linux 6. | ||||||||||||||
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OpenIPMI: invalid permissions
Package(s): | OpenIPMI | CVE #(s): | CVE-2011-4339 | ||||||||||||
Created: | January 14, 2013 | Updated: | January 17, 2013 | ||||||||||||
Description: | From the CVE entry:
ipmievd (aka the IPMI event daemon) in OpenIPMI, as used in the ipmitool package 1.8.11 in Red Hat Enterprise Linux (RHEL) 6, Debian GNU/Linux, Fedora 16, and other products uses 0666 permissions for its ipmievd.pid PID file, which allows local users to kill arbitrary processes by writing to this file. | ||||||||||||||
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pl: code execution
Package(s): | pl | CVE #(s): | CVE-2012-6090 CVE-2012-6089 | ||||||||||||||||
Created: | January 15, 2013 | Updated: | December 6, 2013 | ||||||||||||||||
Description: | From the CVE entries:
Multiple stack-based buffer overflows in the expand function in os/pl-glob.c in SWI-Prolog before 6.2.5 and 6.3.x before 6.3.7 allow remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted filename. (CVE-2012-6090) Multiple stack-based buffer overflows in the canoniseFileName function in os/pl-os.c in SWI-Prolog before 6.2.5 and 6.3.x before 6.3.7 allow remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted filename. (CVE-2012-6089) | ||||||||||||||||||
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proftpd-dfsg: privilege escalation
Package(s): | proftpd-dfsg | CVE #(s): | CVE-2012-6095 | ||||||||||||||||||||||||||||
Created: | January 14, 2013 | Updated: | April 8, 2013 | ||||||||||||||||||||||||||||
Description: | From the Debian advisory:
It has been discovered that in ProFTPd, an FTP server, an attacker on the same physical host as the server may be able to perform a symlink attack allowing to elevate privileges in some configurations. | ||||||||||||||||||||||||||||||
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qemu: buffer overflow
Package(s): | qemu-kvm, qemu | CVE #(s): | CVE-2012-6075 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Created: | January 16, 2013 | Updated: | March 13, 2013 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Description: | From the Debian advisory:
It was discovered that the e1000 emulation code in QEMU does not enforce frame size limits in the same way as the real hardware does. This could trigger buffer overflows in the guest operating system driver for that network card, assuming that the host system does not discard such frames (which it will by default). | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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qt: confusing SSL error messages
Package(s): | qt | CVE #(s): | CVE-2012-6093 | ||||||||||||||||||||||||||||||||
Created: | January 14, 2013 | Updated: | February 7, 2013 | ||||||||||||||||||||||||||||||||
Description: | From the Red Hat bugzilla:
A security flaw was found in the way QSslSocket implementation of the Qt, a software toolkit for applications development, performed certificate verification callbacks, when Qt libraries were used with different OpenSSL version than the one, they were compiled against. In such scenario, this would result in a connection error, but with the SSL error list to contain QSslError:NoError instead of proper reason of the error. This might result in a confusing error being presented to the end users, possibly encouraging them to ignore the SSL errors for the site the connection was initiated against. | ||||||||||||||||||||||||||||||||||
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rails: code execution and more
Package(s): | rails | CVE #(s): | CVE-2013-0156 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Created: | January 10, 2013 | Updated: | March 16, 2015 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Description: | From the Debian advisory: It was discovered that Rails, the Ruby web application development framework, performed insufficient validation on input parameters, allowing unintended type conversions. An attacker may use this to bypass authentication systems, inject arbitrary SQL, inject and execute arbitrary code, or perform a DoS attack on the application. Lots more information can be found in the Rails advisory and this analysis. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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rubygem-activerecord: sql injection
Package(s): | rubygem-activerecord | CVE #(s): | CVE-2012-6496 | ||||||||||||||||||||
Created: | January 15, 2013 | Updated: | January 22, 2014 | ||||||||||||||||||||
Description: | From the CVE entry:
SQL injection vulnerability in the Active Record component in Ruby on Rails before 3.0.18, 3.1.x before 3.1.9, and 3.2.x before 3.2.10 allows remote attackers to execute arbitrary SQL commands via a crafted request that leverages incorrect behavior of dynamic finders in applications that can use unexpected data types in certain find_by_ method calls. | ||||||||||||||||||||||
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tcl-snack: code execution
Package(s): | tcl-snack | CVE #(s): | CVE-2012-6303 | ||||||||||||||||||||||||
Created: | January 14, 2013 | Updated: | February 26, 2015 | ||||||||||||||||||||||||
Description: | From the Secunia Advisory:
Two vulnerabilities have been discovered in Snack Sound Toolkit, which can be exploited by malicious people to compromise a user's system. The vulnerabilities are caused due to missing boundary checks in the "GetWavHeader()" function (generic/jkSoundFile.c) when parsing either format sub-chunks or unknown sub-chunks. This can be exploited to cause a heap-based buffer overflow via specially crafted WAV files with overly large chunk sizes specified. Successful exploitation may allow execution of arbitrary code. | ||||||||||||||||||||||||||
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