8.6
HIGH CVSS 4.0
CVE-2016-20047
EKG Gadu 1.9 Local Buffer Overflow via Username Parameter
Description

EKG Gadu 1.9~pre+r2855-3+b1 contains a local buffer overflow vulnerability in the username handling that allows local attackers to execute arbitrary code by supplying an oversized username string. Attackers can trigger the overflow in the strlcpy function by passing a crafted buffer exceeding 258 bytes to overwrite the instruction pointer and execute shellcode with user privileges.

INFO

Published Date :

March 28, 2026, 12:16 p.m.

Last Modified :

March 28, 2026, 12:16 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2016-20047 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 HIGH [email protected]
CVSS 4.0 HIGH 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 HIGH [email protected]
Solution
Update the vulnerable software to a patched version to prevent local code execution via buffer overflow.
  • Update EKG Gadu to a secure version.
  • Apply vendor-supplied patches or updates.
  • Restrict local user access where possible.
  • Sanitize all user-supplied input.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2016-20047.

URL Resource
http://ekg.chmurka.net/
https://www.exploit-db.com/exploits/40392
https://www.vulncheck.com/advisories/ekg-gadu-local-buffer-overflow-via-username-parameter
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2016-20047 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2016-20047 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2016-20047 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2016-20047 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Mar. 28, 2026

    Action Type Old Value New Value
    Added Description EKG Gadu 1.9~pre+r2855-3+b1 contains a local buffer overflow vulnerability in the username handling that allows local attackers to execute arbitrary code by supplying an oversized username string. Attackers can trigger the overflow in the strlcpy function by passing a crafted buffer exceeding 258 bytes to overwrite the instruction pointer and execute shellcode with user privileges.
    Added CVSS V4.0 AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-787
    Added Reference http://ekg.chmurka.net/
    Added Reference https://www.exploit-db.com/exploits/40392
    Added Reference https://www.vulncheck.com/advisories/ekg-gadu-local-buffer-overflow-via-username-parameter
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.