CVE-2021-21747Public exploitNetwork attack vector

Cookie theft via unsanitized cmd reflection

Published Oct 20, 2021 · Updated Aug 3, 2024

Reflective XSS in ZTE MF971R affected firmware allows remote attackers to execute JavaScript in a victim's browser via a crafted URL. The /api/xmlclient/post handler places the unsanitized cmd query parameter into an HTML response, where browser parsing executes the injected markup. Exploitation needs no router login but requires a victim to open the URL; resulting script can read session cookies in the router web-panel context.

CVSS severity6.1
Medium
EPSS probability0.58%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflective XSS in ZTE MF971R affected firmware allows remote attackers to execute JavaScript in a victim's browser via a crafted URL. The /api/xmlclient/post handler places the unsanitized cmd query parameter into an HTML response, where browser parsing executes the injected markup. Exploitation needs no router login but requires a victim to open the URL; resulting script can read session cookies in the router web-panel context.

The record

CVE
CVE-2021-21747
Published
Oct 20, 2021
Updated
Aug 3, 2024
Vendor
ZTE Corporation
Product
MF971R
Classifications
CWE-79, T1203, T1539
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 20, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=BD_ZTE_MF971RV1.0.0B05, BD_PLKPLMF971R1V1.0.0B06, BD_MF971R2V1.0.0B03, BD_ZTE_MF971RS2V1.0.0B03, BD_ZTE_MF971RSV1.0.0B05

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ZTE Corporation · MF971Rversion=BD_ZTE_MF971RV1.0.0B05, BD_PLKPLMF971R1V1.0.0B06, BD_MF971R2V1.0.0B03, BD_ZTE_MF971RS2V1.0.0B03, BD_ZTE_MF971RSV1.0.0B05

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/A:N
6.1Cisco TalosCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
6.1ZTE CorporationCVSS: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.

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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution
T1539Steal Web Session Cookie

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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