CVE-2023-25076: A buffer overflow vulnerability exists in the handling of wildcard backend hosts of SNIProxy 0.6.0-2 and the m

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CRITICAL 9.8REMOTEDOWNGRADE

CVE-2023-25076 is a critical-severity flaw (CVSS 9.8) affecting sniproxy. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A buffer overflow vulnerability exists in the handling of wildcard backend hosts of SNIProxy 0.6.0-2 and the master branch (commit: 822bb80df9b7b345cc9eba55df74a07b498819ba). A specially crafted HTTP or TLS packet can lead to arbitrary code execution. An attacker could send a malicious packet to trigger this vulnerability.

Why this priority

Critical severity
EPSS top 1%: very likely to be exploited
Public exploit reference
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	65.8% (top 1%)
CISA exploited list	No
Weakness	CWE-120
Published	2023-03-30
Last modified	2026-06-17

Publisher (CNA): Talos · Vendor: sniproxy project

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

Am I affected?

Timeline

2023-03-30 15:15 UTCPublished CVE record published
2026-06-17 05:40 UTCUpdated Record last modified

sniproxy project sniproxy DOWNGRADE

Affected: 0.6.0-2 · 0.6.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.6.0-2

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 0.6.0-2 (Debian / Ubuntu)

apt-cache madison sniproxy sudo apt install sniproxy=<VERSION_BEFORE_0.6.0-2> sudo apt-mark hold sniproxy

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

dnf --showduplicates list sniproxy sudo dnf downgrade sniproxy-<VERSION_BEFORE_0.6.0-2> sudo dnf versionlock add sniproxy

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.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora ELN · python-wrapt · FIXED · 2.5.2-1.eln159 · FEDORA-2026-5503ee9370 · source

sudo dnf upgrade --advisory=FEDORA-2026-5503ee9370

Fedora 46 · python-wrapt · FIXED · 2.5.2-1.fc46 · FEDORA-2026-8a83579801 · source

sudo dnf upgrade --advisory=FEDORA-2026-8a83579801

Ubuntu 20.04 · sniproxy · FIXED · 0.6.0-1ubuntu0.1

sudo apt update && sudo apt install --only-upgrade sniproxy dpkg --compare-versions "$(dpkg-query -W -f='${Version}' sniproxy)" ge "0.6.0-1ubuntu0.1" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 22.04 · sniproxy · FIXED · 0.6.0-2ubuntu0.22.04.1

sudo apt update && sudo apt install --only-upgrade sniproxy dpkg --compare-versions "$(dpkg-query -W -f='${Version}' sniproxy)" ge "0.6.0-2ubuntu0.22.04.1" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 24.10 · sniproxy · NOT AFFECTED

Ubuntu 24.04 · sniproxy · FIXED · 0.6.0-2.1build2

sudo apt update && sudo apt install --only-upgrade sniproxy dpkg --compare-versions "$(dpkg-query -W -f='${Version}' sniproxy)" ge "0.6.0-2.1build2" && echo PATCHED || echo STILL-VULNERABLE

Debian 12 · sniproxy · FIXED · 0.6.0-2.1

sudo apt update && sudo apt install --only-upgrade sniproxy dpkg --compare-versions "$(dpkg-query -W -f='${Version}' sniproxy)" ge "0.6.0-2.1" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · sniproxy · FIXED · 0.6.0-2.1

sudo apt update && sudo apt install --only-upgrade sniproxy dpkg --compare-versions "$(dpkg-query -W -f='${Version}' sniproxy)" ge "0.6.0-2.1" && echo PATCHED || echo STILL-VULNERABLE

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: talosintelligence.com/vulnerability_reports/TALOS-2023-1731
Write-up: www.talosintelligence.com/vulnerability_reports/TALOS-2023-1731

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-2023-25076?

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

Is CVE-2023-25076 being exploited?

CVE-2023-25076 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-2023-25076 affect?

CVE-2023-25076 affects sniproxy. Severity is critical (CVSS 9.8). A buffer overflow vulnerability exists in the handling of wildcard backend hosts of SNIProxy 0.6.0-2 and the master branch (commit: 822bb80df9b7b345cc9eba55df74a07b498819ba). A specially crafted HTTP or TLS packet can lead to arbitrary code

How urgent is CVE-2023-25076?

Priority 72/100. Critical severity; EPSS top 1%: very likely to be exploited; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

References

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