CVE-2021-38337Network attack vector

Reflected XSS via unescaped PHP_SELF request path

Published Sep 10, 2021 · Updated May 2, 2025

Reflected XSS in RSVPMaker Excel 1.1 and earlier allows remote attackers to execute arbitrary scripts through a crafted request path. The download.php script reflects the PHP_SELF request-path value into its generated page without neutralizing attacker-controlled script markup. Exploitation requires a user to open the crafted URL; the script then runs in that user's browser context and can read or alter page-accessible data.

CVSS severity6.1
Medium
EPSS probability0.90%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in RSVPMaker Excel 1.1 and earlier allows remote attackers to execute arbitrary scripts through a crafted request path. The download.php script reflects the PHP_SELF request-path value into its generated page without neutralizing attacker-controlled script markup. Exploitation requires a user to open the crafted URL; the script then runs in that user's browser context and can read or alter page-accessible data.

The record

CVE
CVE-2021-38337
Published
Sep 10, 2021
Updated
May 2, 2025
Vendor
Carr Communications Inc.
Product
RSVPMaker Excel
Classifications
CWE-79, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 10, 2021CVE publishedPublication date reported by the CVE source.
  2. May 2, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.1 <=1.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Carr Communications Inc. · RSVPMaker Excelversion=1.1 <=1.1

Published CVSS scores

6.1WordfenceCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.001Malicious Link

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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