Format string vulnerability in the inputAnswer function in file.c in w3m before 0.5.2, when run with the dump or backend option, allows remote attackers to execute arbitrary code via format string specifiers in the Common Name (CN) field of an SSL certificate associated with an https URL.
The product uses a function that accepts a format string as an argument, but the format string originates from an external source.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| W3m | W3m | 0.5.1 (including) | 0.5.1 (including) |
| W3m | Ubuntu | dapper | * |
| W3m | Ubuntu | devel | * |
| W3m | Ubuntu | edgy | * |
| W3m | Ubuntu | feisty | * |
When an attacker can modify an externally-controlled format string, this can lead to buffer overflows, denial of service, or data representation problems. It should be noted that in some circumstances, such as internationalization, the set of format strings is externally controlled by design. If the source of these format strings is trusted (e.g. only contained in library files that are only modifiable by the system administrator), then the external control might not itself pose a vulnerability.