The Mozilla Project reports: Security researcher Hanno Böck reported that calculations with mp_div and mp_exptmod in Network Security Services (NSS) can produce wrong results in some circumstances. These functions are used within NSS for a variety of cryptographic division functions, leading to potential cryptographic weaknesses. External references: https://www.mozilla.org/en-US/security/advisories/mfsa2016-07/ https://blog.fuzzing-project.org/37-Mozilla-NSS-Wrong-calculation-results-in-mp_div-and-mp_exptmod.html https://github.com/hannob/bignum-fuzz/blob/master/CVE-2016-1938-nss-mp_div.c https://github.com/hannob/bignum-fuzz/blob/master/CVE-2016-1938-nss-mp_exptmod.c https://hg.mozilla.org/projects/nss/diff/a555bf0fc23a/lib/freebl/mpi/mpi.c
This issue has been addressed upstream via nss-3.21