CVE-2020-0665

An elevation of privilege vulnerability exists in Active Directory Forest trusts due to a default setting that lets an attacker in the trusting forest request delegation of a TGT for an identity from the trusted forest, aka ‘Active Directory Elevation of Privilege Vulnerability’.

Recent assessments:

cdelafuente-r7 at May 29, 2020 7:39pm UTC reported:

This vulnerability enables attackers to break the security boundaries that an Active Directory forest claims to maintain. This is due to a flaw in Kerberos and forest trusts themselves. No details were disclosed so far, but the author (@_dirkjan) is going to talk about it at Blackhat Asia later this year (if Mr. Covid lets it happen).

This issue reminds me of this attack disclosed in 2018, which also targets Active Directory forest security boundaries. This leads to a complete compromise of resources in any forest with a two-way interforest trust. According to Microsoft advisory, the severity of @_dirkjan’s vulnerability is only rated as Important. If the level of compromise is similar than 2018’s attack, I believe it is much more critical.

Assessed Attacker Value: 5
Assessed Attacker Value: 5Assessed Attacker Value: 2