If you do not have RHEL subscription, Oracle was kind enough to release updated packages for your old RH4 box.
For both (i386 and X86_64) systems do:
mkdir glibc2015
cd glibc2015
For i386 system do (Note, I had to replace http with h**p to avoid spam filters here.) :
wget h**p://public-yum.oracle.com/repo/EnterpriseLinux/EL4/latest/i386/getPackage/glibc-2.3.4-2.57.0.1.el4.1.i686.rpm
wget h**p://public-yum.oracle.com/repo/EnterpriseLinux/EL4/latest/i386/getPackage/glibc-common-2.3.4-2.57.0.1.el4.1.i386.rpm
wget h**p://public-yum.oracle.com/repo/EnterpriseLinux/EL4/latest/i386/getPackage/glibc-devel-2.3.4-2.57.0.1.el4.1.i386.rpm
wget h**p://public-yum.oracle.com/repo/EnterpriseLinux/EL4/latest/i386/getPackage/glibc-headers-2.3.4-2.57.0.1.el4.1.i386.rpm
For X86_64 system do:
wget h**p://public-yum.oracle.com/repo/EnterpriseLinux/EL4/latest/x86_64/getPackage/glibc-2.3.4-2.57.0.1.el4.1.i686.rpm
wget h**p://public-yum.oracle.com/repo/EnterpriseLinux/EL4/latest/x86_64/getPackage/glibc-2.3.4-2.57.0.1.el4.1.x86_64.rpm
wget h**p://public-yum.oracle.com/repo/EnterpriseLinux/EL4/latest/x86_64/getPackage/glibc-common-2.3.4-2.57.0.1.el4.1.x86_64.rpm
wget h**p://public-yum.oracle.com/repo/EnterpriseLinux/EL4/latest/x86_64/getPackage/glibc-common-2.3.4-2.57.x86_64.rpm
wget h**p://public-yum.oracle.com/repo/EnterpriseLinux/EL4/latest/x86_64/getPackage/glibc-devel-2.3.4-2.57.0.1.el4.1.x86_64.rpm
wget h**p://public-yum.oracle.com/repo/EnterpriseLinux/EL4/latest/x86_64/getPackage/glibc-headers-2.3.4-2.57.0.1.el4.1.x86_64.rpm
For all systems:
rpm -Uvh glibc*rpm
If you get an error about nscd depending on glibc, it is is OK to do:
rpm -Uvh glibc*rpm --nodeps
Remember to restart all network aware services after the update. If you are unsure which services, it might not hurt just to restart the server.