CVE-2016-20047 EKG Gadu 1.9 Local Buffer Overflow via Username Parameter
Local attackers can execute arbitrary code by supplying an oversized username string to trigger a buffer overflow in EKG Gadu.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2016-20047?
CVE-2016-20047 is a high-severity memory corruption vulnerability in EKG Gadu, published on 28 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-787
Which versions are affected by CVE-2016-20047?
How do I fix CVE-2016-20047?
No fix has been published for CVE-2016-20047 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2016-20047 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2016-20047 exists.
Sources
Also known as GHSA-v8g9-6wqg-f384.