A format string exploit occurs when the data of an input string is evaluated as a command by the program. This class of attacks is very similar to buffer overflows since an attacker could execute code, read the stack or cause new behaviors that compromise security. Learn more about format string attacks on OWASP attack index.
If format strings can be influenced by an attacker, they can be exploited.
The highlighted line of code below is the trigger point of this particular Fedora 24 format weakness.
* distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /* * sdbm - ndbm work-alike hashed database library * tuning and portability constructs [not nearly enough] * author: email@example.com */ #ifndef SDBM_TUNE_H #define SDBM_TUNE_H #include "apr_errno.h" /* ### this might be better off as sizeof(char *) */ #define BYTESIZ 8 /* * misc */ #ifdef DEBUG #define debug(x) printf x #else #define debug(x) #endif #endif /* SDBM_TUNE_H */