teler-waf subject to Bypass of Common Web Attack Threat Rule with HTML Entities PayloadGHSA-9f95-hhg4-pg4f
MEDIUMFix: kitabisa/teler-waf@d1d49cfGHSA-9f95-hhg4-pg4f is a medium-severity (CVSS 6.1) CWE-80 vulnerability in github.com/kitabisa/teler-waf. A fix is available for github.com/kitabisa/teler-waf — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-9f95-hhg4-pg4f.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
github.com/kitabisa/teler-wafReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Description
teler-waf is a Go HTTP middleware that provides teler IDS functionality to protect against web-based attacks. Versions prior to v0.1.1 are vulnerable to bypassing common web attack rules when a specific HTML entities payload is used. This vulnerability allows an attacker to execute arbitrary JavaScript code on the victim's browser and compromise the security of the web application. The vulnerability exists due to teler-waf failure to properly sanitize and filter HTML entities in user input.
Impact
An attacker can exploit this vulnerability to bypass common web attack threat rules in teler-waf and launch cross-site scripting (XSS) attacks. The attacker can execute arbitrary JavaScript code on the victim's browser and steal sensitive information, such as login credentials and session tokens, or take control of the victim's browser and perform malicious actions.
Patches
Version v0.1.1 includes a patch for this vulnerability.
Workarounds
We advised updating their installations to version v0.1.1 and frontwards immediately.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/kitabisa/teler-waf | all versions | 0.1.1go get github.com/kitabisa/teler-waf@v0.1.1 |
Affected Products
teler-wafkitabisaDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/kitabisa/teler-waf, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/kitabisa/teler-waf to 0.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9f95-hhg4-pg4f is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is GHSA-9f95-hhg4-pg4f in your dependencies?
Find it across Go, including transitive dependencies.