1. Symantec/
  2. Security Response/
  3. Security Updates Detail

Security Advisories Relating to Symantec Products - PGP Desktop Unsigned Data Insertion


November 18, 2010

Revision History




Remote AccessYes
Local AccessYes
Authentication RequiredNo
Exploit publicly availableProof of Concept


PGP Desktop versions are vulnerable to a data insertion vulnerability. Unsigned (insecure) data could be inserted into OpenPGP messages signed by a trusted source. When the message is decrypted and verified, PGP Desktop may incorrectly identify the message as being fully valid.

Product(s) Affected

PGP Desktop for Windows and OS X10.0.3 and priorUpgrade to 10.0.3SP2
PGP Desktop for Windows and OS X10.1.0Upgrade to 10.1.0 SP1

Product(s) Not Affected

PGP Command Line9.6 and greater


Symantec was notified of a data insertion vulnerability identified in PGP Desktop versions. As defined in RFC 4880, OpenPGP messages are composed of "packets" of information. For example, an OpenPGP message may contain data, signatures, encrypted content, etc. Typically, messages are signed and encrypted, or perhaps just signed, or just encrypted. If a file is signed, there is assurance that it came from a known source (the signer), and was not tampered with.

A skilled attacker, who could successfully intercept an OpenPGP encrypted message from a sender and retransmit to the original recipient, could insert unsigned packets into the OpenPGP message containing signed data. In some circumstances, PGP Desktop will output both the signed and unsigned data, and verify the data as being signed, even though it contains unsigned data.

Alternately, the attacker could insert encrypted data into an OpenPGP message that contains signed and encrypted data. If done successfully, PGP Desktop will output both the encrypted data and the encrypted and signed data, and report that the signature was verified.

A malicious individual with physical access to stored OpenPGP messages can also perform this attack off-line, by inserting the unsigned data into the stored file contents.

The following matrix describes how PGP Desktop is vulnerable to these attacks, either by decrypting and verifying the data with PGP Desktop itself, or by right-clicking the OpenPGP message file and choosing to decrypt and verify.

 PGP Desktop for Windows
 Unsigned Data Alongside Signed DataEncrypted Data Alongside Encrypted+Signed Data
Decrypt/Verify File in PGP DesktopNot VulnerableNot Vulnerable
Decrypt/Verify File via Right-ClickVulnerableVulnerable

 PGP Desktop for OS X
 Unsigned Data Alongside Signed DataEncrypted Data Alongside Encrypted+Signed Data
Decrypt/Verify File in PGP DesktopNot VulnerableVulnerable
Decrypt/Verify File via Right-ClickNot VulnerableVulnerable

Note: Double-clicking an OpenPGP (.pgp) message file will cause the file to be opened for decryption and verification in PGP Desktop.

Symantec Response

PGP product engineers have developed and released a solution. Concerned PGP customers can download Service Pack updates for 10.0.3 and 10.1 by contacting PGP Customer Support.


Users of affected versions of PGP Desktop for Windows should open files for decryption and verification from within the PGP Desktop application, by selecting File->Open and browsing to the file name. Alternately, double-click the file icon to have it opened in PGP Desktop automatically.


Symantec thanks Eric Verheul, Digital Security group, Radbound University Nijmengen for identifying and reporting this issue.


Security Focus, http://www.securityfocus.com, has assigned a Bugtraq ID (BID) 44920 to this issue for inclusion in the Security Focus vulnerability database.

This issue is a candidate for inclusion in the Common Vulnerabilities and Exposures (CVE) list (http://cve.mitre.org). The CVE initiative has assigned CVE-2010-3618 to this issue.


Symantec takes the security and proper functionality of our products very seriously. As founding members of the Organization for Internet Safety (OISafety), Symantec supports and follows responsible disclosure guidelines.
Symantec has developed a Software Security Vulnerability Management Process document outlining the process we follow in addressing suspected vulnerabilities in our products.
Symantec Corporation firmly believes in a proactive approach to secure software development and implements security review into various stages of the software development process. Additionally, Symantec is committed to the security of its products and services as well as to its customers’ data. Symantec is committed to continually improving its software security process.
This document provides an overview of the current Secure Development Lifecycle (SDLC) practice applicable to Symantec’s product and service teams as well as other software security related activities and policies used by such teams. This document is intended as a summary and does not represent a comprehensive list of security testing and practices conducted by Symantec in the software development process.
Please contact secure@symantec.com if you believe you have discovered a security issue in a Symantec product. A member of the Symantec Software Security team will contact you regarding your submission to coordinate any required response. Symantec strongly recommends using encrypted email for reporting vulnerability information to secure@symantec.com.
The Symantec Software Security PGP key can be found at the following location:
Permission to redistribute this alert electronically is granted as long as it is not edited in any way unless authorized by Symantec Software Security. Reprinting the whole or part of this alert in any medium other than electronically requires permission from secure@symantec.com.
Last modified on: November 18, 2010
Security Response Blog
The State of Spam