CVE•Published 2019-12-16•Modified 2026-07-28•0 articles on news•5 live references•NVD data

CVE-2019-16779Excon_project · Excon

Vulnerability data via NVD (ingested)

CVSS v3.1

5.8

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:N/A:N

EPSS percentile

Exploit Prediction Scoring System · top 30% of all CVEs

Weaknesses (CWE)

CWE-664Improper Control of a Resource Through its Lifetime CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Description

In RubyGem excon before 0.71.0, there was a race condition around persistent connections, where a connection which is interrupted (such as by a timeout) would leave data on the socket. Subsequent requests would then read this data, returning content from the previous response. The race condition window appears to be short, and it would be difficult to purposefully exploit this.

Timeline

Published 2019-12-16

Modified 2026-07-28

External references

NVD MITRE Exploit-DB GitHub PoC VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2019-16779

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Excon Project Excon"

All exposed Excon Project Excon instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Excon"

HTTP body or banner mentions "Excon" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2019-16779