In OpenLDAP through 2.4.57 and 2.5.x through 2.5.1alpha, an assertion failure in slapd can occur in the issuerAndThisUpdateCheck function via a crafted packet, resulting in a denial of service (daemon exit) via a short timestamp. This is related to schema_init.c and checkTime.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-27212
• https://bugs.openldap.org/show_bug.cgi?id=9454
• https://git.openldap.org/openldap/openldap/-/commit/3539fc33212b528c56b716584f2c2994af7c30b0
• https://git.openldap.org/openldap/openldap/-/commit/9badb73425a67768c09bcaed1a9c26c684af6c30
• https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b@%3Cissues.bookkeeper.apache.org%3E
• https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4@%3Cissues.bookkeeper.apache.org%3E
• https://lists.debian.org/debian-lts-announce/2021/02/msg00035.html
• https://security.netapp.com/advisory/ntap-20210319-0005/
• https://www.debian.org/security/2021/dsa-4860