CVE-2018-5002
Adobe Flash Player Stack-based Buffer Overflow Vulnerability
Description
CVE-2018-5002 is a stack-based buffer overflow vulnerability in Adobe Flash Player that could lead to remote code execution. By exploiting this flaw, an attacker can execute arbitrary code on affected systems through specially crafted Flash content. CISA has confirmed active exploitation and included CVE-2018-5002 in the Known Exploited Vulnerabilities (KEV) catalog, with the required action being to disconnect Flash Player if still in use, as the product has reached end of life. With an EPSS percentile of 97.5%, this vulnerability remains a significant threat to any systems still running Adobe Flash Player.
KEV Information
CVSS Score
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HOpen in CalculatorCWEs
Affected Products
| Vendor | Product | Version |
|---|---|---|
| adobe | flash player desktop runtime | <= 29.0.0.171 |
| adobe | flash player | <= 29.0.0.171 |
| redhat | enterprise linux desktop | 6.0 |
| redhat | enterprise linux server | 6.0 |
| redhat | enterprise linux workstation | 6.0 |
Multiple CVSS Assessments
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
References
- http://www.securityfocus.com/bid/104412(Broken Link, Third Party Advisory, VDB Entry)
- http://www.securitytracker.com/id/1041058(Broken Link, Third Party Advisory, VDB Entry)
- https://access.redhat.com/errata/RHSA-2018:1827(Third Party Advisory)
- https://helpx.adobe.com/security/products/flash-player/apsb18-19.html(Patch, Vendor Advisory)
- https://security.gentoo.org/glsa/201806-02(Third Party Advisory)
- https://github.com/cisagov/vulnrichment/issues/196(Issue Tracking)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-5002(Third Party Advisory, US Government Resource)
Weakness Type
CWE-121: Stack-based Buffer Overflow
CWE-121 describes a weakness where a program copies data to a buffer on the stack without proper bounds checking, allowing an attacker to overwrite adjacent stack memory including return addresses and local variables. In CVE-2018-5002, Adobe Flash Player fails to properly validate the size of data written to a stack buffer, allowing an attacker to overflow the buffer and redirect execution to attacker-controlled code.
Learn more: CWE-121 — Stack-based Buffer Overflow
Impact Analysis
CVE-2018-5002 is a stack-based buffer overflow vulnerability in Adobe Flash Player that enables remote code execution. The attack is network-based and can be triggered through malicious Flash content embedded in web pages, documents, or emails. No authentication is required, and user interaction is limited to opening or viewing content containing the malicious Flash object. Successful exploitation allows an attacker to execute arbitrary code with the privileges of the user running the Flash Player, which can lead to full system compromise including data theft, malware installation, and lateral movement within the network. The EPSS percentile of 97.5% indicates extremely high exploitation likelihood. Adobe Flash Player has been a perennial target for exploit kits and targeted attacks due to its widespread deployment and rich attack surface. Although Flash Player reached end of life in December 2020, any systems still running it remain critically vulnerable to this and numerous other Flash vulnerabilities.
Exploit Maturity
CISA has confirmed active exploitation of CVE-2018-5002 by including it in the Known Exploited Vulnerabilities catalog with a remediation deadline of June 13, 2022. Notably, CISA's required action states that the impacted product is end-of-life and should be disconnected if still in use, reflecting the fact that Adobe Flash Player no longer receives security patches. The EPSS percentile of 97.5% reflects extensive historical and ongoing exploitation activity. CVE-2018-5002 was exploited as a zero-day in targeted attacks using malicious Excel documents containing embedded Flash content. The exploit was delivered through spear-phishing campaigns targeting specific organizations, with the Flash content designed to download and execute shellcode from an attacker-controlled server. The maturity of Flash Player exploits is exceptionally high, with well-understood techniques for achieving reliable code execution through stack buffer overflows.
Remediation
- Uninstall Adobe Flash Player from all systems immediately. Flash Player reached end of life in December 2020 and no longer receives security updates. CISA's required action explicitly states that the product should be disconnected if still in use.
- Block Flash content at the network perimeter using web proxies, email gateways, and content filtering solutions to prevent Flash-based exploits from reaching endpoints.
- Verify that all web browsers have Flash Player disabled or removed. Modern browsers have removed Flash support entirely, but legacy browser versions may still have it enabled.
- Audit enterprise environments for any remaining Flash Player installations using software inventory tools, as legacy applications and embedded systems may still have Flash Player installed.
- If specific business applications require Flash content, evaluate migration to modern HTML5-based alternatives and implement strict network isolation for any systems that must temporarily retain Flash Player.
Technical Details
CVE-2018-5002 is a stack-based buffer overflow vulnerability in Adobe Flash Player's ActionScript 3 runtime. The vulnerability exists in the processing of certain ActionScript operations that write data to stack-allocated buffers without proper bounds validation. An attacker can craft Flash content (SWF files) that triggers a buffer overflow condition on the stack, overwriting the saved return address and other control data with attacker-specified values. This allows the attacker to redirect program execution to shellcode or a ROP (Return-Oriented Programming) chain that achieves arbitrary code execution. The exploit was observed in the wild being delivered through specially crafted Excel documents that contained embedded Flash objects — when the victim opened the Excel file, the Flash content was loaded and the exploit was triggered. The exploit used a multi-stage payload delivery mechanism where the initial Flash content downloaded additional shellcode from a remote server, making the attack more flexible and harder to detect with static analysis of the initial document.
Frequently Asked Questions
Is CVE-2018-5002 being actively exploited?
Yes, CVE-2018-5002 was actively exploited as a zero-day in targeted spear-phishing campaigns using malicious Excel documents. CISA has included it in the KEV catalog, and its EPSS percentile of 97.5% confirms extensive exploitation. Since Flash Player is end-of-life, no further patches will be issued.
What products are affected by CVE-2018-5002?
CVE-2018-5002 affects Adobe Flash Player across all platforms. Since Flash Player reached end of life in December 2020 and no longer receives updates, all remaining installations are permanently vulnerable.
How do I fix CVE-2018-5002?
Uninstall Adobe Flash Player completely from all systems. There is no patch-based fix since Flash Player is end-of-life. Block Flash content at the network level and verify that all browsers have Flash support disabled or removed.
How severe is CVE-2018-5002?
CVE-2018-5002 is a critical stack buffer overflow enabling remote code execution with an EPSS percentile of 97.5%. The severity is compounded by Flash Player's end-of-life status, meaning the vulnerability will never be patched. Any system still running Flash Player is permanently at risk.
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