Code execution via overlong AddAttachments string
Published Aug 21, 2025 · Updated May 15, 2026
Stack-based buffer overflow in CommuniCrypt Mail 1.16 and earlier allows remote attackers to execute code via crafted web content. The ANSMTP.dll and AOSMTP.dll ActiveX controls copy an overlong AddAttachments() string past a fixed stack buffer and overwrite exception-handler data. Exploitation requires a Windows user to load attacker-controlled content that instantiates the control, enabling code execution in that user's process.
Summary
What happened
Stack-based buffer overflow in CommuniCrypt Mail 1.16 and earlier allows remote attackers to execute code via crafted web content. The ANSMTP.dll and AOSMTP.dll ActiveX controls copy an overlong AddAttachments() string past a fixed stack buffer and overwrite exception-handler data. Exploitation requires a Windows user to load attacker-controlled content that instantiates the control, enabling code execution in that user's process.
The record
- CVE
- CVE-2010-20119
- Published
- Aug 21, 2025
- Updated
- May 15, 2026
- Vendor
- CommuniCrypt Software
- Product
- CommuniCrypt Mail
- Classifications
- CWE-121, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 21, 2025CVE publishedPublication date reported by the CVE source.
- May 15, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <=1.16
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- CommuniCrypt Mail 1.16 ANSMTP.dll/AOSMTP.dll ActiveX exploitproof of concept · unverified
- CommuniCrypt Mail 1.16 SMTP ActiveX Stack Buffer Overflow Metasploit modulefunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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