Microsoft Exchange Server 2013 CU23/2016 CU17/2016 CU18/2019 CU6/2019 CU7 information disclosure
|CVSS Meta Temp Score|
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|Current Exploit Price (≈)|
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|CTI Interest Score|
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A vulnerability classified as critical was found in Microsoft Exchange Server 2013 CU23/2016 CU17/2016 CU18/2019 CU6/2019 CU7 (Groupware Software). Affected by this vulnerability is an unknown code block. The manipulation with an unknown input leads to a information disclosure vulnerability. The CWE definition for the vulnerability is CWE-200. As an impact it is known to affect confidentiality, integrity, and availability.
The weakness was shared 10/13/2020 as confirmed security guidance (Website). It is possible to read the advisory at portal.msrc.microsoft.com. This vulnerability is known as CVE-2020-16969 since 08/04/2020. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/18/2020). The advisory points out:
An information disclosure vulnerability exists in how Microsoft Exchange validates tokens when handling certain messages. An attacker who successfully exploited the vulnerability could use this to gain further information from a user. To exploit the vulnerability, an attacker could include specially crafted OWA messages that could be loaded, without warning or filtering, from the attacker-controlled URL. This callback vector provides an information disclosure tactic used in web beacons and other types of tracking systems. The security update corrects the way that Exchange handles these token validations.
It is declared as proof-of-concept.
Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.
CVSSv3VulDB Meta Base Score: 6.9
VulDB Meta Temp Score: 6.2
VulDB Base Score: 7.1
VulDB Temp Score: 6.4
VulDB Vector: 🔒
VulDB Reliability: 🔍
Vendor Base Score (Microsoft): 7.1
Vendor Vector (Microsoft): 🔒
NVD Base Score: 6.5
NVD Vector: 🔒
VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍
NVD Base Score: 🔒
ExploitingClass: Information disclosure
Price Prediction: 🔍
Current Price Estimation: 🔒
Threat IntelligenceThreat: 🔍
Reaction Time: 🔒
0-Day Time: 🔒
Exposure Time: 🔒
Timeline08/04/2020 CVE assigned
10/13/2020 +70 days Advisory disclosed
10/13/2020 +0 days Countermeasure disclosed
10/14/2020 +0 days VulDB entry created
11/18/2020 +35 days VulDB last update
CVE: CVE-2020-16969 (🔒)
EntryCreated: 10/14/2020 08:55 AM
Updated: 11/18/2020 08:57 PM
Changes: (14) vulnerability_cvss3_nvd_av vulnerability_cvss3_nvd_ac vulnerability_cvss3_nvd_pr vulnerability_cvss3_nvd_ui vulnerability_cvss3_nvd_s vulnerability_cvss3_nvd_c vulnerability_cvss3_nvd_i vulnerability_cvss3_nvd_a vulnerability_cvss2_nvd_av vulnerability_cvss2_nvd_ac vulnerability_cvss2_nvd_au vulnerability_cvss2_nvd_ci vulnerability_cvss2_nvd_ii vulnerability_cvss2_nvd_ai
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