CVE-2020-28502Public exploitNetwork attack vector

Code execution via unescaped synchronous request data

Published Mar 5, 2021 · Updated Sep 16, 2024

Code injection in xmlhttprequest before 1.7.0 and xmlhttprequest-ssl before 1.6.2 allows attackers to execute JavaScript. For synchronous requests, xhr.send embeds request data in an execString passed to a spawned Node process while escaping apostrophes but not backslashes. Exploitation requires an application to pass attacker-controlled data into a synchronous send; injected JavaScript runs with that application's privileges.

CVSS severity8.1
High
EPSS probability4.65%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Code injection in xmlhttprequest before 1.7.0 and xmlhttprequest-ssl before 1.6.2 allows attackers to execute JavaScript. For synchronous requests, xhr.send embeds request data in an execString passed to a spawned Node process while escaping apostrophes but not backslashes. Exploitation requires an application to pass attacker-controlled data into a synchronous send; injected JavaScript runs with that application's privileges.

The record

CVE
CVE-2020-28502
Published
Mar 5, 2021
Updated
Sep 16, 2024
Vendor
Dan DeFelippi
Product
xmlhttprequest
Classifications
CWE-94, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 5, 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

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=unspecified <1.7.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Dan DeFelippi · xmlhttprequestversion=unspecified <1.7.0
Michael de Wit · xmlhttprequest-sslversion=0 <unspecified

Published CVSS scores

9.8GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.1SnykCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
6.8NVDAV:N/AC:M/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-94Improper Control of Generation of Code ('Code Injection')
T1059.007JavaScript/JScript

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo