Adobe Acrobat Reader AcroForms buttonGetCaption use after free

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
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CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.9$5k-$25k0.00

Summaryinfo

A vulnerability was found in Adobe Acrobat Reader up to 2017.011.30199/2020.004.30006/2021.005.20060. It has been declared as critical. This vulnerability affects the function buttonGetCaption of the component AcroForms Handler. Such manipulation leads to use after free. This vulnerability is referenced as CVE-2021-39838. It is possible to launch the attack remotely. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Adobe Acrobat Reader up to 2017.011.30199/2020.004.30006/2021.005.20060 (Document Reader Software) and classified as critical. Affected by this issue is the function buttonGetCaption of the component AcroForms Handler. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability.

The weakness was published 09/30/2021 as apsb21-55. The advisory is shared for download at helpx.adobe.com. This vulnerability is handled as CVE-2021-39838 since 08/23/2021. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 09/30/2021).

Upgrading eliminates this vulnerability.

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Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.0
VulDB Meta Temp Score: 6.9

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

CNA Base Score: 7.8
CNA Vector (Adobe Systems Incorporated): 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Timelineinfo

08/23/2021 🔍
09/30/2021 +38 days 🔍
09/30/2021 +0 days 🔍
10/04/2021 +4 days 🔍

Sourcesinfo

Vendor: adobe.com

Advisory: apsb21-55
Status: Confirmed

CVE: CVE-2021-39838 (🔍)
GCVE (CVE): GCVE-0-2021-39838
GCVE (VulDB): GCVE-100-183560

Entryinfo

Created: 09/30/2021 07:02
Updated: 10/04/2021 07:34
Changes: 09/30/2021 07:02 (52), 10/04/2021 07:34 (1)
Complete: 🔍
Cache ID: 216::103

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