CVE-2021-22889Public exploitNetwork attack vector

Reflected XSS via unescaped statsBreakdown attribute

Published Mar 25, 2021 · Updated Aug 3, 2024

Reflected XSS in Revive Adserver 5.1.1 and earlier allows remote attackers to execute JavaScript via a crafted statsBreakdown value. The _loadPeriodPresetParam method passes the stored value to htmlspecialchars without ENT_QUOTES, leaving single quotes available to inject an onclick attribute. Exploitation requires a user with interface access to open the crafted URL and press a complex key combination; the vendor states that JavaScript cannot access or steal the session cookie.

CVSS severity4.3
Medium
EPSS probability36.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in Revive Adserver 5.1.1 and earlier allows remote attackers to execute JavaScript via a crafted statsBreakdown value. The _loadPeriodPresetParam method passes the stored value to htmlspecialchars without ENT_QUOTES, leaving single quotes available to inject an onclick attribute. Exploitation requires a user with interface access to open the crafted URL and press a complex key combination; the vendor states that JavaScript cannot access or steal the session cookie.

The record

CVE
CVE-2021-22889
Published
Mar 25, 2021
Updated
Aug 3, 2024
Vendor
Revive Adserver Project
Product
Revive Adserver
Classifications
CWE-79, T1203
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=Fixed in v5.2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Revive Adserver Project · Revive Adserverversion=Fixed in v5.2.0

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
4.3Revive AdserverCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/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
Privilegesunauthenticated
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

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Your stack

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