CVE-2021-42009
Apache Traffic Control Traffic Ops Email Injection Vulnerability
An authenticated Apache Traffic Control Traffic Ops user with Portal-level privileges can send a request with a specially-crafted email subject to the /deliveryservices/request Traffic Ops endpoint to send an email, from the Traffic Ops server, with an arbitrary body to an arbitrary email address. Apache Traffic Control 5.1.x users should upgrade to 5.1.3 or 6.0.0. 4.1.x users should upgrade to 5.1.3.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
An authenticated Apache Traffic Control Traffic Ops user with Portal-level privileges can send a request with a specially-crafted email subject to the /deliveryservices/request Traffic Ops endpoint to send an email, from the Traffic Ops server, with an arbitrary body to an arbitrary email address. Apache Traffic Control 5.1.x users should upgrade to 5.1.3 or 6.0.0. 4.1.x users should upgrade to 5.1.3.
- Record
CVE-2021-42009- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N - CVSS 2.0
- 4.0 Medium
AV:N/AC:L/Au:S/C:N/I:P/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
CVE List No score
Apache Traffic Control Traffic Ops Email Injection Vulnerability
An authenticated Apache Traffic Control Traffic Ops user with Portal-level privileges can send a request with a specially-crafted email subject to the /deliveryservices/request Traffic Ops endpoint to send an email, from the Traffic Ops server, with an arbitrary body to an arbitrary email address. Apache Traffic Control 5.1.x users should upgrade to 5.1.3 or 6.0.0. 4.1.x users should upgrade to 5.1.3.
- Record
CVE-2021-42009- Weakness
- CWE-20
- Updated
- 2026-11-02
EUVDEUVD-2021-2206 No score
An authenticated Apache Traffic Control Traffic Ops user with Portal-level privileges can send a request with a specially-crafted email subject to the /deliveryservices/request Traffic Ops endpoint to send an email, from the Traffic Ops server, with an arbitrary body to an arbitrary email address. Apache Traffic Control 5.1.x users should upgrade to 5.1.3 or 6.0.0. 4.1.x users should upgrade to 5.1.3.
- Record
EUVD-2021-2206- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-gw97-f6h8-gm94
Email relay in Apache Traffic Control
An authenticated Apache Traffic Control Traffic Ops user with Portal-level privileges can send a request with a specially-crafted email subject to the /deliveryservices/request Traffic Ops endpoint to send an email, from the Traffic Ops server, with an arbitrary body to an arbitrary email address. Apache Traffic Control 5.1.x users should upgrade to 5.1.3 or 6.0.0. 4.1.x users should upgrade to 5.1.3.
- Record
GHSA-gw97-f6h8-gm94- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
OSV
An authenticated Apache Traffic Control Traffic Ops user with Portal-level privileges can send a request with a specially-crafted email subject to the /deliveryservices/request Traffic Ops endpoint to send an email, from the Traffic Ops server, with an arbitrary body to an arbitrary email address. Apache Traffic Control 5.1.x users should upgrade to 5.1.3 or 6.0.0. 4.1.x users should upgrade to 5.1.3.
- Record
CVE-2021-42009- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N - Updated
- 2026-11-02
OSVGHSA-gw97-f6h8-gm94
Email relay in Apache Traffic Control
An authenticated Apache Traffic Control Traffic Ops user with Portal-level privileges can send a request with a specially-crafted email subject to the /deliveryservices/request Traffic Ops endpoint to send an email, from the Traffic Ops server, with an arbitrary body to an arbitrary email address. Apache Traffic Control 5.1.x users should upgrade to 5.1.3 or 6.0.0. 4.1.x users should upgrade to 5.1.3.
- Record
GHSA-gw97-f6h8-gm94- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
OSVGO-2022-0602 No score
Email relay in Apache Traffic Control in github.com/apache/trafficcontrol
Email relay in Apache Traffic Control in github.com/apache/trafficcontrol
- Record
GO-2022-0602- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
github.com/apache/trafficcontrolGo |
before 5.1.3 | 5.1.3 |
github.com/apache/trafficcontrolGo |
before 5.1.3+incompatible | 5.1.3+incompatible |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-42009 is a medium vulnerability (CVSS 4.3) in Apache Traffic Control, published October 12, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.82%, the 86th percentile. Fixed in github.com/apache/trafficcontrol 5.1.3.
References
lists.apache.org/thread.html/re384fd0f44c6d230f31376153c6e8b59e4a669f927c1533d06d702af%40%3Cdev.trafficcontrol.apache.org%3E
openwall.com/lists/oss-security/2021/10/12/1
nvd.nist.gov/vuln/detail/CVE-2021-42009
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github.com/advisories/GHSA-gw97-f6h8-gm94