lxc-user-nic in lxc through 5.0.1 is installed setuid root, and may allow local users to infer whether any file exists, even within a protected directory tree, because "Failed to open" often indicates that a file does not exist, whereas "does not refer to a network namespace path" often indicates that a file exists. NOTE: this is different from CVE-2018-6556 because the CVE-2018-6556 fix design was based on the premise that "we will report back to the user that the open() failed but the user has no way of knowing why it failed"; however, in many realistic cases, there are no plausible reasons for failing except that the file does not exist. https://github.com/MaherAzzouzi/CVE-2022-47952 https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1783591/comments/45 https://github.com/lxc/lxc/blob/0b83d71c2c8f3bac9503f894cd84584f79258bb3/lxc.spec.in#L274 https://github.com/lxc/lxc/blob/0b83d71c2c8f3bac9503f894cd84584f79258bb3/src/lxc/cmd/lxc_user_nic.c#L1085-L1104
Created lxc tracking bugs for this issue: Affects: epel-all [bug 2157282] Affects: fedora-all [bug 2157283]
This CVE Bugzilla entry is for community support informational purposes only as it does not affect a package in a commercially supported Red Hat product. Refer to the dependent bugs for status of those individual community products.