CVE-2020-35942Network attack vector

Remote code execution via missing nonce check

Published Feb 9, 2021 · Updated Aug 4, 2024

Cross-Site Request Forgery in NextGEN Gallery before 3.5.0 allows remote attackers to execute code through crafted settings requests. The is_authorized_request function accepts POST requests when the nonce parameter is absent, allowing an administrator’s browser to upload a double-extension CSS file and select it as a legacy template for local inclusion and execution. Exploitation requires tricking an administrator into clicking a crafted link and a published album that the attacker can access; injected JavaScript also produces stored cross-site scripting.

CVSS severity8.8
High
EPSS probability1.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-Site Request Forgery in NextGEN Gallery before 3.5.0 allows remote attackers to execute code through crafted settings requests. The is_authorized_request function accepts POST requests when the nonce parameter is absent, allowing an administrator’s browser to upload a double-extension CSS file and select it as a legacy template for local inclusion and execution. Exploitation requires tricking an administrator into clicking a crafted link and a published album that the attacker can access; injected JavaScript also produces stored cross-site scripting.

The record

CVE
CVE-2020-35942
Published
Feb 9, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-352, CWE-79, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 9, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record 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

8.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NVDAV:N/AC:M/Au:N/C:P/I:P/A:P

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-352Cross-Site Request Forgery (CSRF)
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.001User Execution: Malicious 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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