CVE-2021-42305 Microsoft Exchange Server Spoofing Vulnerability
Medium 6.5
Published
Updated
Check this codebase for CVE-2021-42305 and fix it if it is affected.
What it is: CVE-2021-42305 is a medium-severity vulnerability in Microsoft Exchange Server, published on 10 Nov 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-42305 in the wild and no public exploit code.
Affected product: Microsoft Exchange Server. No package-level version data is available, so check the vendor advisory linked from the reference page.
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-2021-42305/ (Markdown: https://insights.sbomify.com/CVE-2021-42305/index.md)
An attacker can spoof email headers in Microsoft Exchange Server, bypassing security controls and misleading recipients.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2021-42305?
CVE-2021-42305 is a medium-severity vulnerability in Microsoft Exchange Server, published on 10 Nov 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Microsoft Exchange Server Spoofing Vulnerability
Which versions are affected by CVE-2021-42305?
It affects 1 product.
Products include Microsoft Exchange Server.
How do I fix CVE-2021-42305?
No fix has been published for CVE-2021-42305 yet. Limit exposure of the affected software until one is available.
Is CVE-2021-42305 being exploited?
There is no known exploitation of CVE-2021-42305 in the wild and no public exploit code.
Other vulnerabilities in Microsoft Exchange Server
- CVE-2024-21410 Microsoft Exchange Server Privilege Escalation
- CVE-2021-34473 Microsoft Exchange Server Remote Code Execution
- CVE-2021-26855 Microsoft Exchange Server Remote Code Execution
- CVE-2021-34523 Microsoft Exchange Server Privilege Escalation
- CVE-2023-21529 Microsoft Exchange Server Deserialization of Untrusted Data
Sources
Also known as GHSA-ch43-44fr-3cm6.