elf/dl-load.c in the GNU C Library (aka glibc or libc6) 2.19 through 2.26 mishandles RPATH and RUNPATH containing $ORIGIN for a privileged (setuid or AT_SECURE) program, which allows local users to gain privileges via a Trojan horse library in the current working directory, related to the fillin_rpath and decompose_rpath functions. This is associated with misinterpretion of an empty RPATH/RUNPATH token as the ./ directory. NOTE: this configuration of RPATH/RUNPATH for a privileged program is apparently very uncommon; most likely, no such program is shipped with any common Linux distribution.
The product searches for critical resources using an externally-supplied search path that can point to resources that are not under the product’s direct control.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Glibc | Gnu | 2.19 (including) | 2.19 (including) |
| Glibc | Gnu | 2.20 (including) | 2.20 (including) |
| Glibc | Gnu | 2.21 (including) | 2.21 (including) |
| Glibc | Gnu | 2.22 (including) | 2.22 (including) |
| Glibc | Gnu | 2.23 (including) | 2.23 (including) |
| Glibc | Gnu | 2.25 (including) | 2.25 (including) |
| Glibc | Gnu | 2.26 (including) | 2.26 (including) |
This might allow attackers to execute their own programs, access unauthorized data files, or modify configuration in unexpected ways. If the product uses a search path to locate critical resources such as programs, then an attacker could modify that search path to point to a malicious program, which the targeted product would then execute. The problem extends to any type of critical resource that the product trusts. Some of the most common variants of untrusted search path are: