CyberSecBulletin
CVE-2023-21612NVD status: Modified

Acrobat Reader: Creation of Temporary File in Directory with Insecure Permissions

Published Updated By the CyberSecBulletin desk

CVE-2023-21612 is a high-severity creation of temporary file in directory with insecure permissions vulnerability in Acrobat Reader from Adobe, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected Acrobat Reader versions: 20.005.30418 and earlier; 22.003.20282 and earlier; 22.003.20281 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.4% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Acrobat Reader you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on helpx.adobe.com for workarounds and exact fixed builds.
  3. 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
AdobeAcrobat Reader20.005.30418 and earlier; 22.003.20282 and earlier; 22.003.20281 and earlierNot stated
AdobeAcrobat Dc15.008.20082 through 22.003.20282; 15.008.20082 through 22.003.20281Not stated
AdobeAcrobat Reader Dc15.008.20082 through 22.003.20282; 15.008.20082 through 22.003.20281Not stated
AdobeAcrobat20.001.30005 through 20.005.30418Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
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:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by CNA (adobe.com).

Official description

Adobe Acrobat Reader versions 22.003.20282 (and earlier), 22.003.20281 (and earlier) and 20.005.30418 (and earlier) are affected by a Creation of Temporary File in Directory with Incorrect Permissions vulnerability that could result in privilege escalation in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

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

The underlying weakness: Creation of Temporary File in Directory with Insecure Permissions

The product creates a temporary file in a directory whose permissions allow unintended actors to determine the file's existence or otherwise access that file.

How developers prevent this class of flaw

  • Many contemporary languages have functions which properly handle this condition. Older C temp file functions are especially susceptible.
  • Try to store sensitive tempfiles in a directory which is not world readable -- i.e., per-user directories.
  • Avoid using vulnerable temp file functions.

More Creation of Temporary File in Directory with Insecure Permissions vulnerabilities (CWE-379)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Acrobat Reader

All Acrobat Reader vulnerabilities

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