An issue was discovered in py-lmdb 0.97. For certain values of mp_flags, mdb_page_touch does not properly set up mc->mc_pg[mc->top], leading to an invalid write operation. NOTE: this outcome occurs when accessing a data.mdb file supplied by an attacker.

References

• https://nvd.nist.gov/vuln/detail/CVE-2019-16225
• https://github.com/TeamSeri0us/pocs/tree/master/lmdb/lmdb%20write%20to%20illegal%20address