Updated glibc packages that fix a security flaw in the resolver as well as dlclose handling are now available.
The GNU libc packages (known as glibc) contain the standard C libraries used by applications. A security audit of the glibc packages in CentOS Linux 2.1 found a flaw in the resolver library which was originally reported as affecting versions of ISC BIND 4.9. This flaw also applied to glibc versions before 2.3.2. An attacker who is able to send DNS responses (perhaps by creating a malicious DNS server) could remotely exploit this vulnerability to execute arbitrary code or cause a denial of service. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2002-0029 to this issue. These updated packages also fix a dlclose function bug on certain shared libraries, which caused program crashes. All users of glibc should upgrade to these updated packages, which resolve these issues.