Buffer overflow in Ekg Gadu
CVE-2016-20047
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.4 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.002 (3.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 3.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
- Ekg Gadu — versions 1:1.9~pre+r2855-3+b1
Weakness classification (CWE)
References
- www.exploit-db.com/exploits/40392 (exploit)
- ekg.chmurka.net/ (product)
- www.vulncheck.com/advisories/ekg-gadu-local-buffer-overflow-via-username-parame… (third-party-advisory)
Frequently asked questions
- What is CVE-2016-20047?
- CVE-2016-20047 is a high-severity vulnerability in Ekg Gadu, classified under Out-of-bounds Write. CVSS score: 8.4/10. Published 2026-03-28.
- How severe is CVE-2016-20047?
- High severity. CVSS v3 base score is 8.4 out of 10.