CVE-2021-21783Network attack vector

Unauthenticated code execution via soap_decode buffer overflow

Published Mar 25, 2021 · Updated Aug 3, 2024

Buffer overflow in the WS-Addressing plugin in Genivia gSOAP 2.8.109 and 2.8.110 allows remote attackers to execute code via SOAP. The soap_decode function checks unsigned size_t values for negativity, allowing a length calculation to wrap and subsequent URI credential decoding to overrun its buffer. Unauthenticated HTTP access to a service built with the affected plugin is sufficient, and successful exploitation runs code in the service context.

CVSS severity9.8
Critical
EPSS probability4.98%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in the WS-Addressing plugin in Genivia gSOAP 2.8.109 and 2.8.110 allows remote attackers to execute code via SOAP. The soap_decode function checks unsigned size_t values for negativity, allowing a length calculation to wrap and subsequent URI credential decoding to overrun its buffer. Unauthenticated HTTP access to a service built with the affected plugin is sufficient, and successful exploitation runs code in the service context.

The record

CVE
CVE-2021-21783
Published
Mar 25, 2021
Updated
Aug 3, 2024
Vendor
Genivia
Product
gSOAP
Classifications
CWE-190, CWE-680, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 25, 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

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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=Genivia gSOAP 2.8.109, Genivia gSOAP 2.8.110

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Genivia · gSOAPversion=Genivia gSOAP 2.8.109, Genivia gSOAP 2.8.110

Published CVSS scores

9.8Cisco TalosCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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 exploitUnconfirmed

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound
CWE-680Integer Overflow to Buffer Overflow
T1190Exploit Public-Facing Application

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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