CVE Vulnerabilities

CVE-2021-26857

Deserialization of Untrusted Data

Published: Mar 03, 2021 | Modified: Mar 07, 2025
CVSS 3.x
7.8
HIGH
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS 2.x
6.8 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P
RedHat/V2
RedHat/V3
Ubuntu

Microsoft Exchange Server Remote Code Execution Vulnerability

Weakness

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

Affected Software

Name Vendor Start Version End Version
Exchange_server Microsoft 2010-sp3 (including) 2010-sp3 (including)
Exchange_server Microsoft 2013-cumulative_update_22 (including) 2013-cumulative_update_22 (including)
Exchange_server Microsoft 2013-cumulative_update_23 (including) 2013-cumulative_update_23 (including)
Exchange_server Microsoft 2013-sp1 (including) 2013-sp1 (including)
Exchange_server Microsoft 2016-cumulative_update_10 (including) 2016-cumulative_update_10 (including)
Exchange_server Microsoft 2016-cumulative_update_11 (including) 2016-cumulative_update_11 (including)
Exchange_server Microsoft 2016-cumulative_update_12 (including) 2016-cumulative_update_12 (including)
Exchange_server Microsoft 2016-cumulative_update_13 (including) 2016-cumulative_update_13 (including)
Exchange_server Microsoft 2016-cumulative_update_14 (including) 2016-cumulative_update_14 (including)
Exchange_server Microsoft 2016-cumulative_update_15 (including) 2016-cumulative_update_15 (including)
Exchange_server Microsoft 2016-cumulative_update_16 (including) 2016-cumulative_update_16 (including)
Exchange_server Microsoft 2016-cumulative_update_17 (including) 2016-cumulative_update_17 (including)
Exchange_server Microsoft 2016-cumulative_update_18 (including) 2016-cumulative_update_18 (including)
Exchange_server Microsoft 2016-cumulative_update_19 (including) 2016-cumulative_update_19 (including)
Exchange_server Microsoft 2016-cumulative_update_8 (including) 2016-cumulative_update_8 (including)
Exchange_server Microsoft 2016-cumulative_update_9 (including) 2016-cumulative_update_9 (including)
Exchange_server Microsoft 2019 (including) 2019 (including)
Exchange_server Microsoft 2019-cumulative_update_1 (including) 2019-cumulative_update_1 (including)
Exchange_server Microsoft 2019-cumulative_update_2 (including) 2019-cumulative_update_2 (including)
Exchange_server Microsoft 2019-cumulative_update_3 (including) 2019-cumulative_update_3 (including)
Exchange_server Microsoft 2019-cumulative_update_4 (including) 2019-cumulative_update_4 (including)
Exchange_server Microsoft 2019-cumulative_update_5 (including) 2019-cumulative_update_5 (including)
Exchange_server Microsoft 2019-cumulative_update_6 (including) 2019-cumulative_update_6 (including)
Exchange_server Microsoft 2019-cumulative_update_7 (including) 2019-cumulative_update_7 (including)
Exchange_server Microsoft 2019-cumulative_update_8 (including) 2019-cumulative_update_8 (including)

Potential Mitigations

  • Make fields transient to protect them from deserialization.
  • An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.

References