CVE-2017-16030
An attacker could edit their own headers, creating an arbitrarily long useragent string, causing the event loop and server to block.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.14%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Useragent is used to parse useragent headers. It uses several regular expressions to accomplish this. An attacker could edit their own headers, creating an arbitrarily long useragent string, causing the event loop and server to block. This affects Useragent 2.1.12 and earlier.
- CVSS 3.0
- 7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 1.14% probability · 67th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-400
- Affected
- useragent project/useragent
- Source
- support@hackerone.com
EPSS 1.1% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://nodesecurity.io/advisories/312Exploit, Third Party Advisory
- https://nodesecurity.io/advisories/312Exploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.