CyberSecBulletin
CVE-2016-0984Exploited in the wildNVD status: Analyzed

Adobe Flash Player and AIR Use-After-Free

Published Updated By the CyberSecBulletin desk

CVE-2016-0984 is a high-severity use after free vulnerability in Flash Player from Adobe, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected Flash Player versions: 20.0.0.272 and earlier; 11.2.202.559 and earlier; 18.0.0.326 and earlier, 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 May 25, 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 products are end-of-life and should be disconnected if still in use.
  3. Read the advisory on helpx.adobe.com for workarounds and exact fixed builds.
  4. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
  5. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
AdobeFlash Player20.0.0.272 and earlier; 11.2.202.559 and earlier; 18.0.0.326 and earlier; 20.0.0.286 and earlierNot stated
AdobeFlash Player Desktop Runtime20.0.0.286 and earlierNot stated
AdobeAir Desktop Runtime20.0.0.233 and earlierNot stated
AdobeAir SDK20.0.0.233 and earlierNot stated
AdobeAir SDK & Compiler20.0.0.233 and earlierNot 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
RequiredA user must take an action such as opening a file or link.
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:R/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.8HighNVD
CVSS 3.18.8HighCISA (ADP)
CVSS 2.09.3HighNVD

Official description

Use-after-free vulnerability in Adobe Flash Player before 18.0.0.329 and 19.x and 20.x before 20.0.0.306 on Windows and OS X and before 11.2.202.569 on Linux, Adobe AIR before 20.0.0.260, Adobe AIR SDK before 20.0.0.260, and Adobe AIR SDK & Compiler before 20.0.0.260 allows attackers to execute arbitrary code via unspecified vectors, a different vulnerability than CVE-2016-0973, CVE-2016-0974, CVE-2016-0975, CVE-2016-0982, and CVE-2016-0983.

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 vulnerabilities in Flash Player

All Flash Player vulnerabilities

Recent Use After Free vulnerabilities

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