# CVE-2024-27305: SMTP smuggling in aiosmtpd > Attackers can spoof sender addresses in inbound emails via SMTP smuggling, enabling phishing attacks against aiosmtpd users. - **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 12 Mar 2024 - **Updated:** 2 Aug 2024 - **Also known as:** DEBIAN-CVE-2024-27305, GHSA-pr2m-px7j-xg65, OESA-2024-1276, OESA-2024-1320, OESA-2024-1321, OESA-2024-1322, PYSEC-2024-221, UBUNTU-CVE-2024-27305, openSUSE-SU-2024:13774-1 ## What is CVE-2024-27305? CVE-2024-27305 is a medium-severity vulnerability in aio-libs aiosmtpd, published on 12 Mar 2024. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description aiosmtpd is a reimplementation of the Python stdlib smtpd.py based on asyncio. aiosmtpd is vulnerable to inbound SMTP smuggling. SMTP smuggling is a novel vulnerability based on not so novel interpretation differences of the SMTP protocol. By exploiting SMTP smuggling, an attacker may send smuggle/spoof e-mails with fake sender addresses, allowing advanced phishing attacks. This issue is also existed in other SMTP software like Postfix. With the right SMTP server constellation, an attacker can send spoofed e-mails to inbound/receiving aiosmtpd instances. This issue has been addressed in version 1.4.5. Users are advised to upgrade. There are no known workarounds for this vulnerability. Weakness: CWE-345 (Insufficient Verification of Data Authenticity) ## Which versions are affected by CVE-2024-27305? 3 open source packages ship an affected version, including aiosmtpd. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `aiosmtpd` | PyPI | All versions | 1.4.5 | | `aiosmtpd` | PyPI | All versions | 1.4.5 | | `aiosmtpd` | PyPI | All versions | 1.4.5 | Products: Aio-Libs Aiosmtpd. ## How do I fix CVE-2024-27305? Upgrade aiosmtpd to 1.4.5 or later. ## Is CVE-2024-27305 being exploited? There is no known exploitation of CVE-2024-27305 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2024-27305 and fix it if it is affected. What it is: CVE-2024-27305 is a medium-severity vulnerability in aio-libs aiosmtpd, published on 12 Mar 2024. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2024-27305 in the wild and no public exploit code. Affected packages and fixed versions: - aiosmtpd (PyPI): affected all versions; fixed in 1.4.5 - aiosmtpd (PyPI): affected all versions; fixed in 1.4.5 - aiosmtpd (PyPI): affected all versions; fixed in 1.4.5 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2024-27305/ (Markdown: https://insights.sbomify.com/CVE-2024-27305/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2024-27305 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-27305 - OSV: https://osv.dev/vulnerability/CVE-2024-27305 --- From sbomify Insights: https://insights.sbomify.com/CVE-2024-27305/ Summaries are generated and may contain mistakes; the official description above is the record.