GHSA-cmcx-xhr8-3w9p is a medium-severity (CVSS 5.7) Improper Input Validation vulnerability in uap-core. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether GHSA-cmcx-xhr8-3w9p is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Denial of Service in uap-core when processing crafted User-Agent strings
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
uap-corenpmDescription
Impact
Some regexes are vulnerable to regular expression denial of service (REDoS) due to overlapping capture groups. This allows remote attackers to overload a server by setting the User-Agent header in an HTTP(S) request to maliciously crafted long strings.
Patches
Please update uap-core to >= v0.7.3
Downstream packages such as uap-python, uap-ruby etc which depend upon uap-core follow different version schemes.
Details
Each vulnerable regular expression reported here contains 3 overlapping capture groups. Backtracking has approximately cubic time complexity with respect to the length of the user-agent string.
Regex 1:
\bSmartWatch *\( *([^;]+) *; *([^;]+) *;
is vulnerable in portion *([^;]+) * and can be attacked with
"SmartWatch(" + (" " * 3500) + "z"
e.g.
SmartWatch( z
Regex 2:
; *([^;/]+) Build[/ ]Huawei(MT1-U06|[A-Z]+\d+[^\);]+)[^\);]*\)
is vulnerable in portion \d+[^\);]+[^\);]* and can be attacked with
";A Build HuaweiA" + ("4" * 3500) + "z"
Regex 3:
(HbbTV)/[0-9]+\.[0-9]+\.[0-9]+ \([^;]*; *(LG)E *; *([^;]*) *;[^;]*;[^;]*;\)
is vulnerable in portion *([^;]*) * and can be attacked with
"HbbTV/0.0.0 (;LGE;" + (" " * 3500) + "z"
Regex 4:
(HbbTV)/[0-9]+\.[0-9]+\.[0-9]+ \([^;]*; *(?:CUS:([^;]*)|([^;]+)) *; *([^;]*) *;.*;
is vulnerable in portions *(?:CUS:([^;]*)|([^;]+)) * and *([^;]*) * and can be attacked with
"HbbTV/0.0.0 (;CUS:;" + (" " * 3500) + "z"
"HbbTV/0.0.0 (;" + (" " * 3500) + "z"
"HbbTV/0.0.0 (;z;" + (" " * 3500) + "z"
Reported by Ben Caller @bcaller
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | uap-core | all versions | 0.7.3 |
| 💎RubyGems | user_agent_parser | all versions | 2.6.0 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for uap-core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update uap-core to 0.7.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-cmcx-xhr8-3w9p is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-cmcx-xhr8-3w9p is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-cmcx-xhr8-3w9p. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-cmcx-xhr8-3w9p in your dependencies?
O3 detects GHSA-cmcx-xhr8-3w9p across npm, RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.