CVE-2021-27132Public exploitNetwork attack vector

HTTP response splitting via unsanitized download URL

Published Feb 27, 2021 · Updated Jul 9, 2026

CRLF injection in SerComm AG Combo VD625 firmware AGSOT_2.1.0 allows remote attackers to inject HTTP response headers through a crafted URL. The download function copies the requested URL into Content-Disposition without sanitizing encoded carriage-return and line-feed characters. Network access to the management interface is sufficient; arbitrary response-header insertion is demonstrated, while XSS and code execution remain unproven.

CVSS severity9.8
Critical
EPSS probability16.49%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

CRLF injection in SerComm AG Combo VD625 firmware AGSOT_2.1.0 allows remote attackers to inject HTTP response headers through a crafted URL. The download function copies the requested URL into Content-Disposition without sanitizing encoded carriage-return and line-feed characters. Network access to the management interface is sufficient; arbitrary response-header insertion is demonstrated, while XSS and code execution remain unproven.

The record

CVE
CVE-2021-27132
Published
Feb 27, 2021
Updated
Jul 9, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-74, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 27, 2021CVE publishedPublication date reported by the CVE source.
  2. Jul 9, 2026Record 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

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/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 exploitPublished

Weakness, pattern, technique

CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
T1190Exploit Public-Facing Application

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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