Cyber Resilience

CVE-2021-47775

HighPublic PoC

Published: 15 January 2026

Published
15 January 2026
Modified
15 April 2026
KEV Added
Patch
CVSS Score v4 8.4 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/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
EPSS Score 0.0015 4.3th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2021-47775 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Litexmedia (inferred from references). Its CVSS base score is 8.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 4.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 CM-11 (User-installed Software) and SI-16 (Memory Protection).

Deeper analysis

CVE-2021-47775 is a buffer overflow vulnerability (CWE-787) in YouTube Video Grabber, now referred to as YouTube Downloader version 1.9.9.1. The issue enables attackers to execute arbitrary code by overwriting the Structured Exception Handler (SEH), as detailed in the CVE description published on 2026-01-15.

The vulnerability has a CVSS v3.1 base score of 8.4 (AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating it requires local access but low attack complexity, no privileges, and no user interaction. A local attacker can craft a malicious payload of 712 bytes using SEH manipulation to trigger a bind shell connection on a specified local port, achieving arbitrary code execution with high impacts to confidentiality, integrity, and availability.

References include an exploit at https://www.exploit-db.com/exploits/50471 and the software site at https://www.litexmedia.com/youtube-grabber/. No mitigation or patch details are specified in the provided CVE information.

EU & UK References

Vulnerability details

YouTube Video Grabber, now referred to as YouTube Downloader, 1.9.9.1 contains a buffer overflow vulnerability that allows attackers to execute arbitrary code by overwriting the Structured Exception Handler. Attackers can craft a malicious payload of 712 bytes with SEH manipulation…

more

to trigger a bind shell connection on a specified local port.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
Why these techniques?

Local buffer overflow with SEH overwrite directly enables client-side arbitrary code execution via crafted input to the vulnerable application.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2019-25705Shared CWE-787
CVE-2019-25633Shared CWE-787
CVE-2026-0538Shared CWE-787
CVE-2016-20046Shared CWE-787
CVE-2019-25628Shared CWE-787
CVE-2019-25695Shared CWE-787
CVE-2018-25218Shared CWE-787
CVE-2026-42484Shared CWE-787
CVE-2019-25612Shared CWE-787
CVE-2025-43300Shared CWE-787

Affected Assets

Litexmedia
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

Implements memory safeguards like DEP and ASLR that directly prevent exploitation of buffer overflows via SEH overwrite for arbitrary code execution.

prevent

Requires identification, prioritization, and remediation of flaws like this buffer overflow vulnerability through patching or removal of the affected software.

prevent

Prohibits installation of unapproved user-installed software such as the vulnerable YouTube Downloader, preventing deployment of the exploitable application.

References