CVE-2016-20047 — EKG Gadu 1.9 Local Buffer Overflow via Username Parameter

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HIGH

EKG Gadu 1.9 Local Buffer Overflow via Username Parameter

Published Mar 28, 2026

8.6

HIGH

CVSS 4.0

EPSS 0.15%

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.

Affected products

Vendor Ekg Product EKG Gadu Default
n/a
- Version
  1:1.9~pre+r2855-3+b1
  Status
  affected
  Constraints
  -

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor

Product

Default status

Versions

Ekg

EKG Gadu

n/a

Version	Status	Constraints
1:1.9~pre+r2855-3+b1	affected	-

Remediation

No remediation recorded yet.

Metrics

0.15% 0.00150

Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.

EPSS probability 0.00150

Score over time

Mar–Oct 2026

EPSS v4
EPSS v5

Percentile over time

EPSS v4
EPSS v5

Table of values (3 key points)

Flat stretches are collapsed; showing up to 120 newest points.

Date	Score	Percentile	Model
Oct 1, 2026	0.15% (0.00150)	3.54th	v5 (v2026.06.15)
Jun 15, 2026	0.15% (0.00150)	4.50th	v5 (v2026.06.15)
Mar 28, 2026	0.01% (0.00013)	2.15th	v4 (v2025.03.14)

Weaknesses (1)

CWE-787

Out-of-bounds Write

References (3)

http://ekg.chmurka.net/
product
https://www.exploit-db.com/exploits/40392
exploit
https://www.vulncheck.com/advisories/ekg-gadu-local-buffer-overflow-via-username-parameter
third-party-advisory

Link	Providers	Tags
http://ekg.chmurka.net/		product
https://www.exploit-db.com/exploits/40392		exploit
https://www.vulncheck.com/advisories/ekg-gadu-local-buffer-overflow-via-username-parameter		third-party-advisory