The shmop functions in PHP before 4.4.5, and before 5.2.1 in the 5.x series, do not verify that their arguments correspond to a shmop resource, which allows context-dependent attackers to read and write arbitrary memory locations via arguments associated with an inappropriate resource, as demonstrated by a GD Image resource.
AV:N/AC:L/Au:N/C:P/I:P/A:P
This vulnerability has a 10.41% probability of being exploited in the next 30 days, ranking higher than 96% of all scored CVEs.