Authenticated script execution via unsanitized memo kind
Published Dec 14, 2021 · Updated Aug 3, 2024
Reflected XSS in GNUBOARD5 before 5.4.20 allows local users to execute browser script through a crafted memo kind parameter. In bbs/memo.php, an unexpected GET kind value is concatenated into an alert response without clean_xss_tags sanitization. A valid member session and victim navigation to a crafted memo URL are required, and successful exploitation runs script in the victim's browser context.
Summary
What happened
Reflected XSS in GNUBOARD5 before 5.4.20 allows local users to execute browser script through a crafted memo kind parameter. In bbs/memo.php, an unexpected GET kind value is concatenated into an alert response without clean_xss_tags sanitization. A valid member session and victim navigation to a crafted memo URL are required, and successful exploitation runs script in the victim's browser context.
The record
- CVE
- CVE-2021-3831
- Published
- Dec 14, 2021
- Updated
- Aug 3, 2024
- Vendor
- GNUBOARD
- Product
- GNUBOARD5
- Classifications
- CWE-79, T1203
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 14, 2021CVE publishedPublication date reported by the CVE source.
- 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.
- Affected versionversion=unspecified <5.4.20
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
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
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