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Threats / Barracuda Networks / CVE-2023-2868
CVE-2023-2868 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Barracuda Networks Email Security Gateway (ESG) Appliance vulnerability

Barracuda Email Security Gateway appliance contains improper input validation in .tar file processing, enabling remote command injection attacks.

Verdict

Today item — known-exploited.

An unauthenticated attacker can exploit insufficient validation of user-supplied .tar files to inject and execute arbitrary commands on affected ESG appliances, with active exploitation confirmed in the wild.

CISA KEV Yes · 2023-05-263EPSS 0.86956 (verify live)4Exploit Weaponized · public PoC5
01

Is it exploitable?

— the evidence, ranked above the score
Exploit available
Fully weaponized — public exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
44 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-05-26).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.86956 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Barracuda Networks, Email Security Gateway (ESG) Appliance. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-20 Improper Input Validation.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
02

Who’s exploiting it?

— attribution turns risk into urgency
Attribution not established

No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.

03

Why it matters

— the attack path, told twice: adversary, then board
1

Front door — unauthenticated access narrative 1

Attacker
I craft a malicious .tar file with embedded command injection payloads in file paths or metadata.
Business
Email security infrastructure becomes a direct attack vector for unauthorized code execution.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I upload or submit the crafted .tar file to the ESG appliance without authentication.
Business
Perimeter defenses fail to prevent exploitation of a critical security appliance.
3

Lateral reach — past segmentation narrative 3

Attacker
I achieve remote command execution with the privileges of the ESG service process.
Business
Attacker gains foothold inside the network with access to email traffic and internal systems.
04

What to do

— defensible action
  • Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05

Coverage & confidence

— what we know, and what we don’t

Established (cited)

  • KEV listing (CISA)
  • EPSS probability (FIRST)
  • Weaponized exploit available (VulnCheck)
  • 44 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Public exploit availability
  • Catalogued by Google (CNA)
  • Coverage gaps — stated, not hidden

  • No EUVD / GCVE mirror in feed — single-authority dependency for the identifier.
  • EPSS & exposure are time-varying; verify live at the source.
  • Threat-actor attribution not established from feed data — absence of a name is not absence of compromise.
  • No finder/reporter credit recorded in the public CVE entry — the work behind this find is unattributed.
  • Disclosure & credit2
    Catalogued by GoogleCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.