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.

CVSS v4.0

8.6 HIGHCVSS:4.0/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

CVSS v3.1

8.4 HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

0.15% chance of exploitation in the next 30 days, 4th percentile

Published

2026-03-28

Updated

2026-03-30

Proof-of-concept exploits (1)

• https://www.exploit-db.com/exploits/40392

References

• CVE Record
• NVD entry

Related

• CVE-2016-20046
• CVE-2016-20048
• CVE-2016-20045
• CVE-2016-20049
• CVE-2016-20044
• CVE-2016-20050