oss-sec mailing list archives
Re: CVE request: screen stack overflow (deep recursion)
From: Solar Designer <solar () openwall com>
Date: Thu, 3 Sep 2015 09:36:29 +0300
On Thu, Sep 03, 2015 at 05:25:11AM +0000, Fiedler Roman wrote:
What about "tail -f /var/log/syslog", Apache or other kind of logs for debugging? [Yes, that's often how logs are running over the screen in videos when talking about IT-security]. It's convenient and I'm using screen exactly to avoid any injection of commands via TIOCSTI into my current TTY when a context switch is needed before starting tail, e.g. when working with LXC containers.
"tail -f" on a log file is indeed very common, but it is bad practice (akin to other very common bad practices like a sysadmin going into a user's homedir as root). A safer alternative in terms of terminal escapes is the "F" keypress in "less -nU" (or in "less -nUEX" to more closely resemble "tail -f"). Unfortunately, I am not aware of a command-line option that would do this (that is, assume that "F" was pressed right away) - perhaps one should be added, if it's not already in there. Unfortunately, less is more complicated and has greater attack surface than tail. Maybe this can be partially mitigated by using the C locale with it (no UTF-8), but I did not look into that. Alexander
Current thread:
- CVE request: screen stack overflow (deep recursion) Florian Weimer (Aug 31)
- Re: CVE request: screen stack overflow (deep recursion) cve-assign (Sep 02)
- AW: Re: CVE request: screen stack overflow (deep recursion) Fiedler Roman (Sep 02)
- Re: CVE request: screen stack overflow (deep recursion) Solar Designer (Sep 02)
- Re: CVE request: screen stack overflow (deep recursion) Solar Designer (Sep 03)
- Re: CVE request: screen stack overflow (deep recursion) Kuang-che Wu (Sep 03)
- AW: Re: CVE request: screen stack overflow (deep recursion) Fiedler Roman (Sep 02)
- Re: CVE request: screen stack overflow (deep recursion) cve-assign (Sep 02)