UNIX for Dummies Questions & Answers

I am reviewing group files on unix servers with Solaris 10. I have noticed several errors in the group files in relation to formatting. For example my fields may look like this:

,:
group name:bb
,user3

Those are just examples. It appears as though some fields were shifted from a previous group listing into its own row. I know there are commands and different tools I can use to remove these format issues. My question is, are there any security vunerabilites created by these errors? If so, is there any documentation, or does anyone know of any articles that would discuss them.

The security vulnerabilities would depend on the contents of the file. Seeing two lines of it doesn't allow me to extrapolate the rest.

I see from the Solaris security guide that the ASET tool will check group files for formatting problems an correct them. I was interested in knowing in general what potential security vulnerabilities could be created by having formatting issues in the etc group file. I have these issues in my group file . I am not looking for a specific answer for my server but just for example so you can understand. Group 1 should have a password of xx a gid of 600 and have user1 as the only group member. In my file it would look like this.

Group 1:xx:
600:user1

There are many variations of formatting errors in the file just looking for a general answer to any potential security issues group file formatting problems can create.

The problem is that 'formatting issues' can put anything in the group file. You may have users belonging to groups they shouldn't. You may have users not belonging to groups they should.

The implications of that depend on which groups have been messed up in what way.

The only way that this anomaly could occur is by manual editing of the /etc/group file.
Suggest that you first copy the file, then run the grpck program and clear-up any anomalies with a manal edit as root.

Ps. I can't see any adverse security anomalies from invalid entries in a /etc/group file because this is a strict format file and the invalid entries will be ignored. However, I have seen valid entries after an invalid line being ignored.


Please no space characters in a group name.

Thanks for the help