Find Out If Patch Number ( CVE ) Has Been Applied To RHEL / CentOS Linux

Q. I know how to update my system using yum command. But how can I find out that patch has been applied to a package? How do I search CVE patch number applied to a package under Red Hat / CentOS / RHEL / Fedora Linux?

A. You need to use rpm command. Each rpm package stores information about patches including date, small description and CVE number. You can use the -q query option to display change information for the package.

rpm --changelog option

Use the command as follows:
rpm -q --changelog {package-name}
rpm -q --changelog {package-name} | more
rpm -q --changelog {package-name} | grep CVE-NUMBER

For example find out if CVE-2008-1927 has been applied to perl package or not, enter:
# rpm -q --changelog perl|grep CVE-2008-1927
Sample output:

- CVE-2008-1927 perl: double free on regular expressions with utf8 characters

List all applied patches for php, enter:
# rpm -q --changelog php
Sample output:

* Tue Jun 03 2008 Joe Orton  5.1.6-20.el5_2.1
- add security fixes for CVE-2007-5898, CVE-2007-4782, CVE-2007-5899,
  CVE-2008-2051, CVE-2008-2107, CVE-2008-2108 (#445923)
* Tue Jan 15 2008 Joe Orton  5.1.6-20.el5
- use magic.mime provided by file (#240845)
- fix possible crash with setlocale() (#428675)
* Thu Jan 10 2008 Joe Orton  5.1.6-19.el5
- ext/date: fix test cases for recent timezone values (#266441)
* Thu Jan 10 2008 Joe Orton  5.1.6-18.el5
- ext/date: updates for system tzdata support (#266441)
* Wed Jan 09 2008 Joe Orton  5.1.6-17.el5
- ext/date: use system timezone database (#266441)
* Tue Jan 08 2008 Joe Orton  5.1.6-16.el5
- add dbase extension in -common (#161639)
- add /usr/share/php to builtin include_path (#238455)
- ext/ldap: enable ldap_sasl_bind (#336221)
- ext/libxml: reset stream context (#298031)
.........
...
....
* Fri May 16 2003 Joe Orton  4.3.1-3
- link odbc module correctly
- patch so that php -n doesn't scan inidir
- run tests using php -n, avoid loading system modules
* Wed May 14 2003 Joe Orton  4.3.1-2
- workaround broken parser produced by bison-1.875
* Tue May 06 2003 Joe Orton  4.3.1-1
- update to 4.3.1; run test suite
- open extension modules with RTLD_NOW rather than _LAZY

How do I find CVE for a rpm file itself?

Above command will query installed package only. To query rpm file, enter:
$ rpm -qp --changelog rsnapshot-1.3.0-1.noarch.rpm | more