An issue was discovered in the GNU C Library (glibc) 2.36. When the syslog function is passed a crafted input string larger than 1024 bytes, it reads uninitialized memory from the heap and prints it to the target log file, potentially revealing a portion of the contents of the heap.
Information written to log files can be of a sensitive nature and give valuable guidance to an attacker or expose sensitive user information.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Glibc | Gnu | 2.36 (including) | 2.36 (including) |
| Eglibc | Ubuntu | trusty | * |
| Glibc | Ubuntu | upstream | * |
| Glibc | Ubuntu | xenial | * |
While logging all information may be helpful during development stages, it is important that logging levels be set appropriately before a product ships so that sensitive user data and system information are not accidentally exposed to potential attackers. Different log files may be produced and stored for: