CVE-2020-16956

CVE-2020-16956 is a medium-severity vulnerability in Microsoft Dynamics 365 with a CVSS 3.x base score of 5.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Description

<p>A cross site scripting vulnerability exists when Microsoft Dynamics 365 (on-premises) does not properly sanitize a specially crafted web request to an affected Dynamics server. An authenticated attacker could exploit the vulnerability by sending a specially crafted request to an affected Dynamics server.</p> <p>The attacker who successfully exploited the vulnerability could then perform cross-site scripting attacks on affected systems and run script in the security context of the current authenticated user. These attacks could allow the attacker to read content that the attacker is not authorized to read, use the victim's identity to take actions within Dynamics Server on behalf of the user, such as change permissions and delete content, and inject malicious content in the browser of the user.</p> <p>The security update addresses the vulnerability by helping to ensure that Dynamics Server properly sanitizes web requests.</p>

Frequently asked questions

What is CVE-2020-16956?
<p>A cross site scripting vulnerability exists when Microsoft Dynamics 365 (on-premises) does not properly sanitize a specially crafted web request to an affected Dynamics server. An authenticated attacker could exploit the vulnerability by sending a specially crafted request to an affected Dynamics server.</p> <p>The attacker who successfully exploited the vulnerability could then perform cross-site scripting attacks on affected systems and run script in the security context of the current authenticated user. These attacks could allow the attacker to read content that the attacker is not authorized to read, use the victim's identity to take actions within Dynamics Server on behalf of the user, such as change permissions and delete content, and inject malicious content in the browser of the user.</p> <p>The security update addresses the vulnerability by helping to ensure that Dynamics Server properly sanitizes web requests.</p>
How severe is CVE-2020-16956?
CVE-2020-16956 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2020-16956 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-16956?
CVE-2020-16956 primarily affects Microsoft Dynamics 365. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-16956?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-16956 published?
CVE-2020-16956 was published on 2020-10-16 and last updated on 2026-06-17.

References

Affected products (2)

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