CVE-2021-34559Network attack vector

Cached-link rewriting via inconsistent HTTP parsing

Published Aug 31, 2021 · Updated Sep 16, 2024

HTTP request smuggling in Pepperl+Fuchs WirelessHART Gateway 3.0.8 and earlier allows remote attackers to rewrite cached links and URLs. The advisory identifies inconsistent HTTP request interpretation but does not disclose the parsing discrepancy or affected web-server component. Network access to the gateway is required, and poisoned cached content can redirect subsequent link or URL use.

CVSS severity5.3
Medium
EPSS probability0.77%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

HTTP request smuggling in Pepperl+Fuchs WirelessHART Gateway 3.0.8 and earlier allows remote attackers to rewrite cached links and URLs. The advisory identifies inconsistent HTTP request interpretation but does not disclose the parsing discrepancy or affected web-server component. Network access to the gateway is required, and poisoned cached content can redirect subsequent link or URL use.

The record

CVE
CVE-2021-34559
Published
Aug 31, 2021
Updated
Sep 16, 2024
Vendor
Pepperl+Fuchs
Product
WHA-GW-F2D2-0-AS-Z2-ETH.EIP
Classifications
CWE-444
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 31, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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?

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

  1. Affected versionversion=3.0.8 <=3.0.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Pepperl+Fuchs · WHA-GW-F2D2-0-AS-Z2-ETH.EIPversion=3.0.8 <=3.0.8
Pepperl+Fuchs · WHA-GW-F2D2-0-AS-Z2-ETHversion=3.0.8 <=3.0.8

Published CVSS scores

5.3CERT@VDECVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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 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-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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