CyberSecBulletin
CVE-2015-5122Exploited in the wildNVD status: Analyzed

Adobe Flash Player Use-After-Free

CVE-2015-5122 is a critical-severity use after free vulnerability in Flash Player from Adobe, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Flash Player versions: 13.0 through 13.0.0.302; 18.0 through 18.0.0.203; 18.0 through 18.0.0.204, and others listed below. The record does not name a fixed version, so check the vendor advisory. CISA added it to the Known Exploited Vulnerabilities catalogue on April 13, 2022, which means attacks have been observed in the wild.

Patch now

Attackers are already exploiting this vulnerability, according to CISA.

What to do

  1. Check which version of Flash Player you run against the affected versions below, and install the vendor's latest release.
  2. CISA's required action: The impacted product is end-of-life and should be disconnected if still in use.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
AdobeFlash Player13.0 through 13.0.0.302; 18.0 through 18.0.0.203; 18.0 through 18.0.0.204; 11.0 through 11.2.202.481Not stated
AdobeFlash Player Desktop Runtime18.0 through 18.0.0.203Not stated
Red HatEnterprise Linux Desktop5.0; 6.0Not stated
Red HatEnterprise Linux Server5.0; 6.0Not stated
Red HatEnterprise Linux Server EUS6.6Not stated
Red HatEnterprise Linux Workstation5.0; 6.0Not stated
openSUSEEvergreen11.4Not stated
SUSELinux Enterprise Desktop11; 12Not stated
SUSELinux Enterprise Workstation Extension12Not stated

Version data comes from NVD's product matching. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.19.8CriticalNVD
CVSS 3.17.8HighCISA (ADP)
CVSS 2.010.0HighNVD

Official description

Use-after-free vulnerability in the DisplayObject class in the ActionScript 3 (AS3) implementation in Adobe Flash Player 13.x through 13.0.0.302 on Windows and OS X, 14.x through 18.0.0.203 on Windows and OS X, 11.x through 11.2.202.481 on Linux, and 12.x through 18.0.0.204 on Linux Chrome installations allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via crafted Flash content that leverages improper handling of the opaqueBackground property, as exploited in the wild in July 2015.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

How developers prevent this class of flaw

  • Choose a language that provides automatic memory management.
  • When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.

More Use After Free vulnerabilities (CWE-416)

Timeline

  1. CVE record published.
  2. Added to CISA's Known Exploited Vulnerabilities catalogue.
  3. Deadline for US federal agencies to remediate, set by CISA.
  4. CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
  5. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Technical write-ups (may include proof of concept)

Other references

Other vulnerabilities in Flash Player

All Flash Player vulnerabilities

Recent Use After Free vulnerabilities

Spotted an error? Tell us.