CVE-2021-31209 Microsoft Exchange Server Spoofing Vulnerability
Medium 6.5
Published
Updated
Check this codebase for CVE-2021-31209 and fix it if it is affected.
What it is: CVE-2021-31209 is a medium-severity vulnerability in Microsoft Exchange Server, published on 11 May 2021. 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-2021-31209 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-2021-31209/ (Markdown: https://insights.sbomify.com/CVE-2021-31209/index.md)
Attackers 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
- Not needed
- Fix
- None listed
What is CVE-2021-31209?
CVE-2021-31209 is a medium-severity vulnerability in Microsoft Exchange Server, published on 11 May 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Microsoft Exchange Server Spoofing Vulnerability
Weakness: CWE-290
Which versions are affected by CVE-2021-31209?
It affects 1 product.
Products include Microsoft Exchange Server.
How do I fix CVE-2021-31209?
No fix has been published for CVE-2021-31209 yet. Limit exposure of the affected software until one is available.
Is CVE-2021-31209 being exploited?
There is no known exploitation of CVE-2021-31209 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-v623-3qmp-8rrh.