CVE-2020-13128Public exploitNetwork attack vector

Remote service hang via persistent upload delay

Published May 17, 2020 · Updated Aug 4, 2024

Denial of service in Manolo GWTUpload 1.0.3 allows remote attackers to make a hosting web application unresponsive via file-upload requests. UploadServlet.parsePostRequest stores the unvalidated delay parameter in a servlet field, and AbstractUploadListener.update passes it to Thread.sleep during upload progress. Remote attackers who can reach an upload endpoint can submit files larger than 4,096 bytes and occupy the bounded server thread pool, hanging all request handling.

CVSS severity7.5
High
EPSS probability1.61%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Manolo GWTUpload 1.0.3 allows remote attackers to make a hosting web application unresponsive via file-upload requests. UploadServlet.parsePostRequest stores the unvalidated delay parameter in a servlet field, and AbstractUploadListener.update passes it to Thread.sleep during upload progress. Remote attackers who can reach an upload endpoint can submit files larger than 4,096 bytes and occupy the bounded server thread pool, hanging all request handling.

The record

CVE
CVE-2020-13128
Published
May 17, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-434, T1499.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 17, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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?

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

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/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 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-434Unrestricted Upload of File with Dangerous Type
T1499.002Service Exhaustion Flood

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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