CVE-2021-30134Public exploitNetwork attack vector

Reflected XSS via missing response content types

Published Dec 26, 2022 · Updated Apr 14, 2025

Reflected XSS in php-mod/curl before 2.3.2 allows remote attackers to execute script in a user's browser via exposed test endpoints. The post_file_path_upload.php endpoint JSON-encodes the key parameter without a JSON content type, while post_multidimensional.php echoes raw POST data without a plain-text content type. The test files must be deployed under a web root, and a user must follow the crafted URL; execution remains confined to the vulnerable site's browser origin.

CVSS severity6.1
Medium
EPSS probability1.26%
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 php-mod/curl before 2.3.2 allows remote attackers to execute script in a user's browser via exposed test endpoints. The post_file_path_upload.php endpoint JSON-encodes the key parameter without a JSON content type, while post_multidimensional.php echoes raw POST data without a plain-text content type. The test files must be deployed under a web root, and a user must follow the crafted URL; execution remains confined to the vulnerable site's browser origin.

The record

CVE
CVE-2021-30134
Published
Dec 26, 2022
Updated
Apr 14, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 26, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 14, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
6.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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.

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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 exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

Public exploit references

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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