CVE-2020-15173

Name: CVE-2020-15173
Creator: NVD / NIST
Published: 2020-09-09T23:15:10.977+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 1.18%

Last modified Jun 17, 2026

CVE-2020-15173 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. In ACCEL-PPP (an implementation of PPTP/PPPoE/L2TP/SSTP), there is a buffer overflow when receiving an l2tp control packet ith an AVP which type is a string and no hidden flags, length set to less than 6. If your application is used in open networks or there are untrusted nodes in the network it is highly recommended to apply the patch. EPSS estimates a 1.18% chance of exploitation in the next 30 days.

Description

In ACCEL-PPP (an implementation of PPTP/PPPoE/L2TP/SSTP), there is a buffer overflow when receiving an l2tp control packet ith an AVP which type is a string and no hidden flags, length set to less than 6. If your application is used in open networks or there are untrusted nodes in the network it is highly recommended to apply the patch. The problem was patched with commit 2324bcd5ba12cf28f47357a8f03cd41b7c04c52b As a workaround changes of commit 2324bcd5ba12cf28f47357a8f03cd41b7c04c52b can be applied to older versions.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

1.18%

63.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Accel-Ppp	Accel-Ppp	<= 1.12.0-92-g38b6104

References

https://github.com/accel-ppp/accel-ppp/commit/2324bcd5ba12cf28f47357a8f03cd41b7c04c52bPatch, Third Party Advisory
https://github.com/accel-ppp/accel-ppp/security/advisories/GHSA-rr68-fchr-69vfThird Party Advisory
https://github.com/accel-ppp/accel-ppp/commit/2324bcd5ba12cf28f47357a8f03cd41b7c04c52bPatch, Third Party Advisory
https://github.com/accel-ppp/accel-ppp/security/advisories/GHSA-rr68-fchr-69vfThird Party Advisory

Timeline

Published: Sep 9, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-15173?

How severe is CVE-2020-15173?

CVE-2020-15173 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 1.18% probability of exploitation in the next 30 days.

How do I fix CVE-2020-15173?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-15173?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST