CVE-2021-41437Public exploitNetwork attack vector

Cloud-storage access via HTTP response splitting

Published Sep 26, 2022 · Updated May 21, 2025

HTTP response splitting in ASUS RT-AX88U firmware before 3.0.0.4.388.20558 allows remote attackers to obtain cloud-storage access. The AiCloud web component accepts a crafted URL that splits the HTTP response; published material does not identify the affected handler, parameter, or exact missing neutralization. Exploitation requires an authenticated victim to visit the crafted URL, and the record does not specify whose cloud-storage data becomes accessible.

CVSS severity6.5
Medium
EPSS probability0.97%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

HTTP response splitting in ASUS RT-AX88U firmware before 3.0.0.4.388.20558 allows remote attackers to obtain cloud-storage access. The AiCloud web component accepts a crafted URL that splits the HTTP response; published material does not identify the affected handler, parameter, or exact missing neutralization. Exploitation requires an authenticated victim to visit the crafted URL, and the record does not specify whose cloud-storage data becomes accessible.

The record

CVE
CVE-2021-41437
Published
Sep 26, 2022
Updated
May 21, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-74
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 26, 2022CVE publishedPublication date reported by the CVE source.
  2. May 21, 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

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
6.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

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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