CVE-2018-18820: A buffer overflow was discovered in the URL-authentication backend of the Icecast before 2.4.4

Q: How do I fix CVE-2018-18820?

icecast: upgrade to 2.4.4; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2018-18820 being exploited?

CVE-2018-18820 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-2018-18820 affect?

CVE-2018-18820 affects icecast, debian linux. Severity is high (CVSS 8.1). A buffer overflow was discovered in the URL-authentication backend of the Icecast before 2.4.4. If the backend is enabled, then any malicious HTTP client can send a request for that specific resource including a crafted header, leading to d

Q: How urgent is CVE-2018-18820?

Priority 63/100. High severity; EPSS top 1%: very likely to be exploited; Remotely exploitable, no login, no user action; On your watchlist

This week

HIGH 8.1REMOTEWATCHLISTUPGRADEMITIGATE

CVE-2018-18820 is a high-severity flaw (CVSS 8.1) affecting icecast, debian linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A buffer overflow was discovered in the URL-authentication backend of the Icecast before 2.4.4. If the backend is enabled, then any malicious HTTP client can send a request for that specific resource including a crafted header, leading to denial of service and potentially remote code execution.

Why this priority

High severity
EPSS top 1%: very likely to be exploited
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	8.1 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	48.9% (top 1%)
CISA exploited list	No
Weakness	CWE-119
Published	2018-11-05
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: debian · xiph

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

Am I affected?

Timeline

2018-11-05 19:29 UTCPublished CVE record published
2026-06-17 01:47 UTCUpdated Record last modified

xiph icecast UPGRADE

Affected: < 2.4.4

Fixed in: 2.4.4

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy icecast || rpm -q icecast || icecast --version

2. UPGRADE to 2.4.4 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade icecast

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade icecast

Note

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

debian debian linux MITIGATE

Affected: 8.0 · 9.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

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-2018-18820?

icecast: upgrade to 2.4.4; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2018-18820 being exploited?

CVE-2018-18820 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-2018-18820 affect?

CVE-2018-18820 affects icecast, debian linux. Severity is high (CVSS 8.1). A buffer overflow was discovered in the URL-authentication backend of the Icecast before 2.4.4. If the backend is enabled, then any malicious HTTP client can send a request for that specific resource including a crafted header, leading to d

How urgent is CVE-2018-18820?

Priority 63/100. High severity; EPSS top 1%: very likely to be exploited; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Debian vulnerabilities

Related CVEs

CVE-2015-3026 MEDIUM 5.0 UPGRADE MITIGATE Icecast before 2.4.2, when a stream_auth handler is defined for URL authentication, allows remote attackers to
CVE-2014-9091 MEDIUM 4.6 UPGRADE Icecast before 2.4.0 does not change the supplementary group privileges when <changeowner> is configured, whic
CVE-2014-9018 MEDIUM 5.0 UPGRADE Icecast before 2.4.1 transmits the output of the on-connect script, which might allow remote attackers to obta
CVE-2011-4612 MEDIUM 5.0 UPGRADE icecast before 2.3.3 allows remote attackers to inject control characters such as newlines into the error loc

References

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