Adobe Acrobat and Reader Use-After-Free
CVE-2009-4324 is a high-severity use after free vulnerability in Acrobat 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. The record lists versions 8.2, 9.3 as the first without the flaw, so updating Acrobat to one of those releases or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on June 8, 2022, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update Acrobat to 8.2 or 9.3, whichever matches your release line, or a later version.
- Update Acrobat Reader to 8.2 or 9.3, whichever matches your release line, or a later version.
- CISA's required action: Apply updates per vendor instructions.
- Read the advisory on adobe.com for workarounds and exact fixed builds.
- 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
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Adobe | Acrobat | 8.0 up to, but not including, 8.2; 9.0 up to, but not including, 9.3 | 8.2, 9.3 |
| Adobe | Acrobat Reader | 8.0 up to, but not including, 8.2; 9.0 up to, but not including, 9.3 | 8.2, 9.3 |
| SUSE | Linux Enterprise Debuginfo | 11 | Not stated |
| openSUSE | Opensuse | 11.1; 11.2 | Not stated |
| SUSE | Linux Enterprise | 10.0 | Not 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
- 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 NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
| CVSS 2.0 | 9.3 | High | NVD |
Official description
Use-after-free vulnerability in the Doc.media.newPlayer method in Multimedia.api in Adobe Reader and Acrobat 9.x before 9.3, and 8.x before 8.2 on Windows and Mac OS X, allows remote attackers to execute arbitrary code via a crafted PDF file using ZLib compressed streams, as exploited in the wild in December 2009.
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.
Timeline
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- lists.opensuse.org/opensuse-security-announce/2010-01/msg00009.htmlMailing List, Third Party Advisory
- kb.cert.org/vuls/id/508357Third Party Advisory, US Government Resource
- us-cert.gov/cas/techalerts/TA10-013A.htmlThird Party Advisory, US Government Resource
- exchange.xforce.ibmcloud.com/vulnerabilities/54747Third Party Advisory, VDB Entry
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2009-4324US Government Resource
Technical write-ups (may include proof of concept)
- contagiodump.blogspot.com/2009/12/virustotal-httpwww.htmlExploit, Third Party Advisory
Other references
- adobe.com/support/security/bulletins/apsb10-02.htmlNot Applicable
- bugzilla.redhat.com/show_bug.cgi?id=547799Issue Tracking
Other vulnerabilities in Acrobat
- 8.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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