CVE-2015-8651

HIGH(8.8)KEVLikely Exploited

Adobe Flash Player Integer Overflow Vulnerability

Description

CVE-2015-8651 is an integer overflow vulnerability in Adobe Flash Player that allows attackers to execute arbitrary code on the affected system. The vulnerability occurs when Flash Player processes specially crafted content that triggers an integer overflow condition during memory allocation, leading to heap corruption and ultimately code execution. This Adobe Flash Player vulnerability was widely exploited in targeted attack campaigns. CISA has listed CVE-2015-8651 in the Known Exploited Vulnerabilities catalog, confirming active exploitation, and its EPSS percentile of 99.6% indicates near-certain exploitation activity. The impacted product is end-of-life and should be removed.

KEV Information

Vendor
Adobe
Product
Flash Player
Date Added
May 25, 2022
Due Date
June 15, 2022
Required Action
The impacted product is end-of-life and should be disconnected if still in use.

CVSS Score

Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HOpen in Calculator
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
2.8
Impact Score
5.9

CWEs

Affected Products

VendorProductVersion
adobeair sdk< 20.0.0.233
adobeair sdk \& compiler< 20.0.0.233
adobeflash player< 11.2.202.559; < 18.0.0.324; >= 19.0.0.185, < 20.0.0.267
adobeair< 20.0.0.233
redhatenterprise linux desktop5.0; 6.0
redhatenterprise linux server5.0; 6.0
redhatenterprise linux workstation5.0; 6.0
opensuseevergreen11.4
opensuseopensuse13.1; 13.2
suselinux enterprise desktop11; 12
suselinux enterprise workstation extension12
hpinsight control< 7.6
hpinsight control server provisioning< 7.6
hpmatrix operating environment7.6
hpsystem management homepage< 7.6
hpsystems insight manager< 7.6
hpversion control repository manager< 7.6

Multiple CVSS Assessments

Source: [email protected](Primary)
8.8
HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0(Secondary)
8.8
HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

References

Weakness Type

No specific CWE has been assigned to CVE-2015-8651 in the NVD database. The vulnerability is an integer overflow in Adobe Flash Player. Integer overflow occurs when an arithmetic operation on integer values produces a result that exceeds the storage capacity of the integer type, causing the value to wrap around to a small or negative number. In Flash Player, this wraparound leads to an undersized heap allocation, and when subsequent operations write data into this undersized buffer, heap corruption occurs, enabling the attacker to achieve arbitrary code execution.

Learn more: CWE Overview

Impact Analysis

CVE-2015-8651 enables remote code execution through an integer overflow in Adobe Flash Player. The vulnerability is remotely exploitable through crafted Flash content embedded in web pages, email, or documents. Confidentiality (High): Successful exploitation gives the attacker full access to data accessible by the browser process, including session cookies, cached credentials, and local files. Integrity (High): Arbitrary code execution allows installation of persistent malware, modification of system files, and establishment of command-and-control channels. Availability (High): Compromised systems can be recruited into botnets, used for cryptocurrency mining, or have their data encrypted by ransomware. With an EPSS percentile of 99.6%, this vulnerability has a near-certain probability of active exploitation, making it one of the most exploited Flash Player vulnerabilities ever documented.

Exploit Maturity

CISA has confirmed active exploitation of CVE-2015-8651 and listed it in the Known Exploited Vulnerabilities catalog, with the note that the impacted product is end-of-life and should be disconnected if still in use. The EPSS percentile of 99.6% places this vulnerability among the most actively exploited, indicating near-certain exploitation activity. CVE-2015-8651 was exploited in targeted attack campaigns including state-sponsored operations. The exploit was incorporated into multiple exploit kits used for mass-scale drive-by download campaigns, making it one of the most impactful Flash Player vulnerabilities in terms of both targeted and opportunistic exploitation.

Remediation

  1. Remove Adobe Flash Player entirely from all systems. As stated in the CISA KEV required action, the impacted product is end-of-life and should be disconnected if still in use. Adobe ended Flash Player support on December 31, 2020.
  2. Remove Flash Player browser plugins from all browsers. Verify complete removal using endpoint management tools and software inventory systems.
  3. Migrate Flash-dependent applications to modern web technologies such as HTML5, WebAssembly, and JavaScript. Identify all applications and content that still require Flash Player functionality.
  4. Block Flash content at the network perimeter using web proxies and content filtering to prevent .swf files from being downloaded and executed.
  5. Audit and remove all Flash Player installations across the enterprise, including standalone player installations, AIR runtime, and any embedded Flash components in third-party applications.

Technical Details

CVE-2015-8651 is an integer overflow vulnerability in Adobe Flash Player that leads to heap corruption and arbitrary code execution. The flaw occurs during the processing of specially crafted SWF content where an arithmetic operation on size or length values overflows an integer type, producing a value smaller than expected. This underflow results in an undersized heap buffer allocation. When the Flash runtime subsequently writes data into this buffer using the original (pre-overflow) size, it corrupts adjacent heap memory. The attacker can precisely control the overflow conditions and heap layout through careful SWF content construction, enabling them to overwrite specific heap objects or metadata to redirect program execution. Flash Player's complex object model, JIT compiler, and garbage collector provide numerous target objects in the heap that can be corrupted to achieve reliable code execution across different platforms and configurations.

Frequently Asked Questions

Is CVE-2015-8651 being actively exploited?

Yes, CVE-2015-8651 is actively exploited with near-certain exploitation activity confirmed. CISA listed it in the KEV catalog and noted the product is end-of-life. The EPSS percentile of 99.6% places it among the most exploited vulnerabilities. It was used in both targeted and mass-scale attack campaigns.

What products are affected by CVE-2015-8651?

CVE-2015-8651 affects Adobe Flash Player. The product reached end-of-life on December 31, 2020, and no longer receives security updates. Any remaining installations are permanently vulnerable.

How do I fix CVE-2015-8651?

Completely remove Adobe Flash Player from all systems and browsers. Since the product is end-of-life, no patches are available. Migrate Flash-dependent content to modern web technologies and block Flash content at network boundaries.

How severe is CVE-2015-8651?

CVE-2015-8651 is a remote code execution vulnerability with an EPSS percentile of 99.6%, indicating near-certain exploitation. The severity is compounded by the end-of-life status of Flash Player, confirmed use in state-sponsored attacks, and integration into widely used exploit kits.

CVSS Score

8.8
HIGH(8.8)

EPSS Score

EPSS Score67.92%
EPSS Percentile99.3%

Dates

PublishedDecember 28, 2015
Last ModifiedJune 17, 2026
StatusAnalyzed
CVSS Versionv3.1

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