CVE-2024-55581: When AdaCore Ada Web Server 25.0.0 is linked with GnuTLS, the default behaviour of AWS.Client is vulnerable to

This week

HIGH 7.4REMOTEWATCHLISTDOWNGRADEMITIGATE

CVE-2024-55581 is a high-severity flaw (CVSS 7.4) affecting ada web server, debian linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

When AdaCore Ada Web Server 25.0.0 is linked with GnuTLS, the default behaviour of AWS.Client is vulnerable to a man-in-the-middle attack because of lack of verification of an HTTPS server's certificate (unless the using program specifies a TLS configuration).

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action
On your watchlist

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

Risk facts

CVSS score	7.4 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 78%)
CISA exploited list	No
Weakness	CWE-295
Published	2025-02-26
Last modified	2026-06-17

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

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

Am I affected?

Timeline

2025-02-26 22:15 UTCPublished CVE record published
2026-06-17 08:11 UTCUpdated Record last modified

adacore ada web server DOWNGRADE

Affected: 25.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 25.0

1. Check installed version

apt-cache policy ada-web-server || rpm -q ada-web-server || ada-web-server --version

2. No fixed release: DOWNGRADE to a release before 25.0 (Debian / Ubuntu)

apt-cache madison ada-web-server sudo apt install ada-web-server=<VERSION_BEFORE_25.0> sudo apt-mark hold ada-web-server

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

dnf --showduplicates list ada-web-server sudo dnf downgrade ada-web-server-<VERSION_BEFORE_25.0> sudo dnf versionlock add ada-web-server

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.

debian debian linux MITIGATE

Affected: 11.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 11.0

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-2024-55581?

ada web server: downgrade or apply the listed mitigation; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2024-55581 being exploited?

CVE-2024-55581 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-2024-55581 affect?

CVE-2024-55581 affects ada web server, debian linux. Severity is high (CVSS 7.4). When AdaCore Ada Web Server 25.0.0 is linked with GnuTLS, the default behaviour of AWS.Client is vulnerable to a man-in-the-middle attack because of lack of verification of an HTTPS server's certificate (unless the using program specifies a

How urgent is CVE-2024-55581?

Priority 46/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Debian vulnerabilities · AWS vulnerabilities · GnuTLS vulnerabilities

Related CVEs

CVE-2025-52494 HIGH 7.5 UPGRADE Adacore Ada Web Server (AWS) before 25.2 is vulnerable to a denial-of-service (DoS) condition due to improper

References

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