Security readout for executives and security teams
Plain-English summary
CVE-2020-1456 is a medium-severity cross-site scripting issue in Microsoft SharePoint. An authenticated attacker could send a crafted web request that causes script content to run in another user's browser. Business impact is mainly unauthorized content actions, data exposure, and trust damage inside SharePoint collaboration sites.
Executive priority
Treat as a normal-priority SharePoint security update unless the affected portal is internet-facing, sensitive, or heavily used by privileged staff. It is not KEV-listed in the bundle, but XSS in collaboration systems can still support credential theft or unauthorized actions.
Technical view
The flaw is CWE-79 XSS caused by insufficient sanitization of specially crafted web requests to affected SharePoint servers. CVSS 3.1 is 5.4 with network access, low complexity, low privileges required, user interaction required, changed scope, low confidentiality and integrity impact, and no availability impact.
Likely exposure
Exposure is most likely in organizations running affected Microsoft SharePoint Server 2019 or 2010 SP2, or SharePoint Enterprise Server 2016 or 2013 SP1, especially internet-facing or broadly accessible collaboration portals.
Exploitation context
The bundle does not show CISA KEV listing or confirmed active exploitation. Public researcher references exist, but the provided evidence does not establish exploitation in the wild. The attack requires some privileges and victim interaction, reducing urgency compared with unauthenticated server compromise.
Researcher notes
CVE-2020-1456 is distinct from CVE-2020-1450 and CVE-2020-1451. Assessment should focus on sanitization of crafted requests, authenticated attack paths, and whether user interaction can trigger script execution in another security context. Do not assume broader code execution from the provided evidence.
Mitigation direction
- Review Microsoft MSRC guidance for CVE-2020-1456 and apply the applicable SharePoint updates.
- Inventory affected SharePoint versions and prioritize externally reachable or high-trust portals.
- Restrict SharePoint access to trusted users while remediation is pending.
- Review vendor guidance before relying on workarounds not named in the advisory.
Validation and detection
- Confirm each SharePoint farm version and patch level against the Microsoft advisory.
- Identify affected products: SharePoint Server 2019 or 2010 SP2, Enterprise Server 2016 or 2013 SP1.
- Check whether affected SharePoint sites are internet-facing or broadly accessible internally.
- Review SharePoint and web logs for suspicious crafted requests or unexpected script content.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2020-1456 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N2.32.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.4MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1456CVE reference · x_refsource_MISC
- https://slashcrypto.org/2021/01/15/CVE-2020-1456/CVE reference · x_refsource_MISC
- https://it-sec.de/ger/Aktuelles-Termine/it.sec-blog/it.sec-Research-Team-findet-unbekannte-Schwachstelle-in-Microsoft-Office-SharePointCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.