
Red Hat, Inc. Security Advisory
Package	Screen

Synopsis	screen defaults to not using Unix98 ptys

Advisory ID	RHSA-1999:042-01

Issue Date	1999-10-20

Updated on

Keywords	screen unix98 pty permissions

Cross references	N/A

1. Topic: Screen uses ptys with world read/write permissions. 2. Problem description: The version of screen that shipped with Red Hat Linux 6.1 defaulted to not using Unix98 ptys. Since screen is not setuid root, this means that it leaves the ptys with insecure permissions. The updated packages restore the Unix98 pty support. Thanks go to Chris Evans for noting this vulnerability. Previous versions of Red Hat Linux are not affected by this problem. 3. Bug IDs fixed:(https://bugzilla.redhat.com for more info) 6100 4. Relevant releases/architectures: Red Hat Linux 6.1, for i386 5. Obsoleted by: None 6. Conflicts with: None 7. RPMs required: Intel: screen-3.9.4-3.i386.rpm Source: screen-3.9.4-3.src.rpm Architecture neutral: 8. Solution: For each RPM for your particular architecture, run: rpm -Uvh filename where filename is the name of the RPM. 9. Verification: MD5 sum Package Name ------------------------------------------------------------------------- 2e5ada61d3d06408bae76bf581d2bf69 screen-3.9.4-3.i386.rpm 09277e5b10b709ac2d974b952cb29e9b screen-3.9.4-3.src.rpm These packages are GPG signed by Red Hat Inc. for security. Our key is available at: You can verify each package with the following command: rpm --checksig filename If you only wish to verify that each package has not been corrupted or tampered with, examine only the md5sum with the following command: rpm --checksig --nogpg filename 10. References:

RH6.1: screen (RHSA-1999:042-01)

Screen uses ptys with world read/write permissions

Summary

The version of screen that shipped with Red Hat Linux 6.1defaulted to not using Unix98 ptys. Since screen is not setuidroot, this means that it leaves the ptys with insecure permissions.The updated packages restore the Unix98 pty support. Thanks go toChris Evans for noting this vulnerability.

Previous versions of Red Hat Linux are not affected by this problem.

3. Bug IDs fixed:(https://bugzilla.redhat.com for more info)
6100

Solution

For each RPM for your particular architecture, run:

rpm -Uvh filename

where filename is the name of the RPM.

9. Verification:


 MD5 sum                           Package Name

2e5ada61d3d06408bae76bf581d2bf69  screen-3.9.4-3.i386.rpm
09277e5b10b709ac2d974b952cb29e9b  screen-3.9.4-3.src.rpm

These packages are GPG signed by Red Hat Inc. for security. Our key is available at:

You can verify each package with the following command:

rpm --checksig filename

If you only wish to verify that each package has not been corrupted or
tampered with, examine only the md5sum with the following command:

rpm --checksig --nogpg filename