CVE-2013-5580: The (1) Conn_StartLogin and (2) cb_Read_Resolver_Result functions in conn.c in ngIRCd 18 through 20.2, when th

Routine

MEDIUM 4.3DOWNGRADE

CVE-2013-5580 is a medium-severity flaw (CVSS 4.3) affecting ngircd. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The (1) Conn_StartLogin and (2) cb_Read_Resolver_Result functions in conn.c in ngIRCd 18 through 20.2, when the configuration option NoticeAuth is enabled, does not properly handle the return code for the Handle_Write function, which allows remote attackers to cause a denial of service (assertion failure and server crash) via unspecified vectors, related to a "notice auth" message not being sent to a new client.

Why this priority

No elevated risk signals yet

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	4.3 (Medium)
EPSS exploit chance	2.3% (top 17%)
CISA exploited list	No
Weakness	CWE-20
Published	2013-10-01
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: barton

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2013-10-01 19:55 UTCPublished CVE record published
2026-06-16 23:59 UTCUpdated Record last modified

barton ngircd DOWNGRADE

Affected: 18.0 · 19.0 · 19.1 · 20.0 · 20.1 · 20.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 18.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 18.0 (Debian / Ubuntu)

apt-cache madison ngircd sudo apt install ngircd=<VERSION_BEFORE_18.0> sudo apt-mark hold ngircd

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list ngircd sudo dnf downgrade ngircd-<VERSION_BEFORE_18.0> sudo dnf versionlock add ngircd

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2013-5580?

ngircd: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2013-5580 being exploited?

CVE-2013-5580 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-2013-5580 affect?

CVE-2013-5580 affects ngircd. Severity is medium (CVSS 4.3). The (1) Conn_StartLogin and (2) cb_Read_Resolver_Result functions in conn.c in ngIRCd 18 through 20.2, when the configuration option NoticeAuth is enabled, does not properly handle the return code for the Handle_Write function, which allows

How urgent is CVE-2013-5580?

Priority 36/100. No elevated risk signals yet.

Related CVEs

CVE-2020-14148 HIGH 7.5 UPGRADE MITIGATE The Server-Server protocol implementation in ngIRCd before 26~rc2 allows an out-of-bounds access, as demonstra
CVE-2013-1747 MEDIUM 5.0 DOWNGRADE channel.c in ngIRCd 20 and 20.1 allows remote attackers to cause a denial of service (assertion failure and cr

References

← Back to latest CVEs