CVE-2021-38189 — SMTP command injection in lettre — CVE Details

CRITICAL

SMTP command injection in lettre

Published July 12, 2021Updated November 8, 2023Source: osv

Summary

### Impact Affected versions of lettre allowed SMTP command injection through an attacker's controlled message body. The module for escaping lines starting with a period wouldn't catch a period that was placed after a double CRLF sequence, allowing the attacker to end the current message and write arbitrary SMTP commands after it. ### Fix The flaw is fixed by correctly handling consecutive CRLF sequences. ### References * [RUSTSEC-2021-0069](https://rustsec.org/advisories/RUSTSEC-2021-0069.html)

Advisory Timeline

First published July 12, 2021 (1918 days ago).
Last revised November 8, 2023 — 848 days after initial publication.

Remediation

Upgrade to the fixed version using your package manager.

Cargo

Update lettre to 0.9.6 or later

cargo update -p lettre --precise 0.9.6

After upgrading, run your dependency scanner again to confirm the vulnerability is resolved.

Affected Packages (1)

Affects 1 ecosystem: crates.io (1).

Package	Ecosystem	Affected	Fixed In
lettre	crates.io	All versions	0.9.6

Vulnerability Classification

Common Weakness Enumeration (CWE) identifiers for this vulnerability type.

CWE-147
View on MITRE

CVSS Score Breakdown

What the CVSS (Common Vulnerability Scoring System) 9.8 score means for each attack dimension.

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Frequently Asked Questions

What is CVE-2021-38189?: SMTP command injection in lettre This vulnerability has been assigned a severity rating of CRITICAL (CVSS score: 9.8/10).
How do I check if my project is affected by CVE-2021-38189?: CVE-2021-38189 affects lettre. Use GeekWala's free vulnerability scanner to check your dependencies against CVE-2021-38189 and 200,000+ other known vulnerabilities.

Severity & Exploitability

CVSS Score

9.8

Exploitation is straightforward and causes maximum impact. Patch immediately.

Also Known As

GHSA-qc36-q22q-cjw3

RUSTSEC-2021-0069

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