CVE-2020-15173: In ACCEL-PPP (an implementation of PPTP/PPPoE/L2TP/SSTP), there is a buffer overflow when receiving an l2tp co

Q: How do I fix CVE-2020-15173?

accel-ppp: upgrade to newer than 1.12.0-92-g38b6104. Exact commands for each OS are on this page.

Q: Is CVE-2020-15173 being exploited?

CVE-2020-15173 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2020-15173 affect?

CVE-2020-15173 affects accel-ppp. Severity is high (CVSS 8.2). 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

Q: How urgent is CVE-2020-15173?

Priority 51/100. High severity; Remotely exploitable, no login, no user action

This month

HIGH 8.2REMOTEUPGRADE

CVE-2020-15173 is a high-severity flaw (CVSS 8.2) affecting accel-ppp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	8.2 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.2% (top 32%)
CISA exploited list	No
Weakness	CWE-119, CWE-120
Published	2020-09-09
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: accel-ppp

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-09-09 23:15 UTCPublished CVE record published
2026-06-17 02:56 UTCUpdated Record last modified

accel-ppp accel-ppp UPGRADE

Affected: <= 1.12.0-92-g38b6104

Fixed in: newer than 1.12.0-92-g38b6104

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy accel-ppp || rpm -q accel-ppp || accel-ppp --version

2. UPGRADE to newer than 1.12.0-92-g38b6104 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade accel-ppp

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade accel-ppp

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2020-15173?

accel-ppp: upgrade to newer than 1.12.0-92-g38b6104. Exact commands for each OS are on this page.

Is CVE-2020-15173 being exploited?

CVE-2020-15173 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2020-15173 affect?

CVE-2020-15173 affects accel-ppp. Severity is high (CVSS 8.2). 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

How urgent is CVE-2020-15173?

Priority 51/100. High severity; Remotely exploitable, no login, no user action

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References

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