CVE-2021-24426Public exploitNetwork attack vector

Administrator-session script execution via unescaped tab parameter

Published Jul 12, 2021 · Updated Aug 3, 2024

Reflected XSS in Backup by 10Web 1.0.20 and earlier allows remote authenticated users to run script via a crafted tab value. The affected page writes the tab query parameter into its HTML response without sanitization or output escaping. A logged-in administrator must follow the crafted request; the injected script then runs in that administrator's browser context.

CVSS severity4.8
Medium
EPSS probability0.63%
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

Reflected XSS in Backup by 10Web 1.0.20 and earlier allows remote authenticated users to run script via a crafted tab value. The affected page writes the tab query parameter into its HTML response without sanitization or output escaping. A logged-in administrator must follow the crafted request; the injected script then runs in that administrator's browser context.

The record

CVE
CVE-2021-24426
Published
Jul 12, 2021
Updated
Aug 3, 2024
Vendor
10Web
Product
Backup by 10Web
Classifications
CWE-79, T1203
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jul 12, 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

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=1.0.20 <=1.0.20

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

10Web · Backup by 10Webversion=1.0.20 <=1.0.20

Published CVSS scores

4.8NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
3.5NVDAV:N/AC:M/Au:S/C:N/I:P/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

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