Negative Integer Scale Argument Vulnerability in PHP's bcpowmod Function

CVE-2016-4537 · HIGH Severity

AV:N/AC:L/AU:N/C:P/I:P/A:P

The bcpowmod function in ext/bcmath/bcmath.c in PHP before 5.5.35, 5.6.x before 5.6.21, and 7.x before 7.0.6 accepts a negative integer for the scale argument, which allows remote attackers to cause a denial of service or possibly have unspecified other impact via a crafted call.

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