rAthena is an open-source cross-platform MMORPG server. A use-after-free vulnerability exists in the RODEX functionality of rAthenas map-server in versions prior to commit af2f3ba. An unauthenticated attacker can exploit this vulnerability via a specific attacking scenario to cause a denial of service by crashing the map-server. This issue has been patched in commit af2f3ba. There are no known workarounds aside from manually applying the patch.
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.