CVE-2015-7645

Adobe Flash Player had a serious weakness that can be triggered by opening a specially made Flash file (a “SWF”). If someone convinces a user to open it, the attacker may be able to take over the computer.

Think of it like a “door” that still exists in your building: even if it looks locked, the lock is known to be breakable, and attackers have used it before.

This matters if you run or support computers where Adobe Flash Player is still installed and can be used by users (for example, through a browser or another app that plays Flash). The impacted Flash versions are end-of-life, and CISA’s guidance treats the risk as real in campaigns.

This is only a risk when the affected Flash functionality is reachable from where users can be tricked into opening Flash content (i.e., when Flash is installed and can be used).

This is RED because CISA lists CVE-2015-7645 in its Known Exploited Vulnerabilities set and the required action explicitly says the affected product is end-of-life and should be disconnected if still in use. Public exploits exist and the vulnerability has been used in real-world campaigns.

Treat any system still running the affected Flash versions as actively at risk until Flash is removed or disabled.

Confirm exposure

1. Inventory: On each Windows, macOS, and Linux workstation/server used by staff, check whether “Adobe Flash Player” is installed.
2. Version check: Identify the installed Flash Player version. Mark systems as affected if the version is within:
   • 18.x through 18.0.0.252
   • 19.x through 19.0.0.207
   • 11.x through 11.2.202.535

Remediate

3. Immediate fix (preferred): Remove or disable Adobe Flash Player everywhere it exists.
4. Containment: If any affected machine is currently used for browsing or receiving untrusted content, disconnect it from the network until Flash is removed/disabled.
5. Validate: After changes, confirm Flash playback is blocked in browsers/apps (and that Flash content no longer runs).

Patch guidance

• Vendor security guidance exists for the issue (see the vendor links in the IT message). However, CISA’s KEV required action indicates the impacted product is end-of-life—so in practice, removal/disablement and network containment are the key steps.

What to monitor

• Look for signs of compromise around the time of any user interaction with unknown links/files (suspicious processes launching, unexpected persistence mechanisms, unusual outbound connections).

CVE-2015-7645 is a Flash Player vulnerability that allows remote code execution when an attacker provides a crafted SWF file. KEV (CISA) confirms it has been used in real-world campaigns and sets a remediation due date of 2022-03-24; the required action notes the impacted product is end-of-life and instructs disconnection if still in use. Public exploits have been reported (weaponization), and the vulnerability has been exploited in the wild (noted as exploited in October 2015 in the provided backstop).

Because Flash Player is end-of-life, mitigation is primarily to eliminate the vulnerable component (remove/disable Flash) rather than rely on in-place patching.