Btcpayserver
CVE-2021-3646
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization Output encoding, context-aware escaping
MITRE ATT&CK
2 techniques across 2 tactics: Initial Access, Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 6.1 (MEDIUM). Attack characteristics: network attack vector, low complexity, no privileges required, user interaction required. Public proof-of-concept exploit code is available. |
| Exploit ScenarioDerived | A remote attacker could inject malicious scripts into web pages viewed by other users by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
btcpayserver is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'). Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Sanitize all user input, use Content-Security-Policy headers, encode output contextually (HTML, JS, URL). Use frameworks with built-in XSS protection.
Affects your stack
Find out whether the stacks and servers you run are on an affected version.
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Cross-Site Scripting (XSS) (CWE-79), which allows attackers to inject malicious scripts into web pages viewed by other users. btcpayserver is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') Affected products include: Btcpayserver Btcpay Server.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
btcpayserver is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Cross-Site Scripting occurs when an application accepts untrusted data and sends it to a web browser without proper validation or encoding.
Affected Products (CPE)NVD
More in Btcpayserver
View allImproper Neutralization of Equivalent Special Elements in GitHub repository btcpayserver/btcpayserver prior to 1.7.5. Ra
Open Redirect in GitHub repository btcpayserver/btcpayserver prior to 1.7.6. Rated medium severity (CVSS 6.1), this vuln
Cross-site Scripting in GitHub repository btcpayserver/btcpayserver prior to 1.8.3. Rated medium severity (CVSS 5.4), th
Improper Neutralization of Equivalent Special Elements in GitHub repository btcpayserver/btcpayserver prior to 1.8.0. Ra
Cross-site Scripting (XSS) - Stored in GitHub repository btcpayserver/btcpayserver prior to 1.7.12. Rated medium severit
Cross-site Scripting (XSS) - Stored in GitHub repository btcpayserver/btcpayserver prior to 1.7.11. Rated medium severit
Cross-site Scripting (XSS) - Stored in GitHub repository btcpayserver/btcpayserver prior to 1.7.6. Rated medium severity
btcpayserver is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'). Rate
BTCPay Server before 1.0.6.0, when the payment button is used, has a privacy vulnerability. Rated high severity (CVSS 7.
BTCPay Server through 1.0.7.0 suffers from directory traversal, which allows an attacker with admin privileges to achiev
BTCPay Server before 1.0.7.1 mishandles the policy setting in which users can register (in Server Settings > Policies).
BTCPay Server through 1.0.7.0 suffers from a Stored Cross Site Scripting (XSS) vulnerability within the POS Add Products
Exploit-DB