How severe is CVE-2018-0138?

CVE-2018-0138 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2018-0138 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-0138?

CVE-2018-0138 primarily affects Cisco Firepower Threat Defense. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-0138?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2018-0138 published?

CVE-2018-0138 was published on 2018-02-08 and last updated on 2026-06-17.

CVE-2018-0138

CVE-2018-0138 is a medium-severity vulnerability in Cisco Firepower Threat Defense with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-693.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 1% (64th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-693
Affected product: Cisco Firepower Threat Defense
Published: 2018-02-08
Last modified: 2026-06-17

Description

A vulnerability in the detection engine of Cisco Firepower System Software could allow an unauthenticated, remote attacker to bypass file policies that are configured to block files transmitted to an affected device via the BitTorrent protocol. The vulnerability exists because the affected software does not detect BitTorrent handshake messages correctly. An attacker could exploit this vulnerability by sending a crafted BitTorrent connection request to an affected device. A successful exploit could allow the attacker to bypass file policies that are configured to block files transmitted to the affected device via the BitTorrent protocol. Cisco Bug IDs: CSCve26946.

Frequently asked questions

What is CVE-2018-0138?: A vulnerability in the detection engine of Cisco Firepower System Software could allow an unauthenticated, remote attacker to bypass file policies that are configured to block files transmitted to an affected device via the BitTorrent protocol. The vulnerability exists because the affected software does not detect BitTorrent handshake messages correctly. An attacker could exploit this vulnerability by sending a crafted BitTorrent connection request to an affected device. A successful exploit could allow the attacker to bypass file policies that are configured to block files transmitted to the affected device via the BitTorrent protocol. Cisco Bug IDs: CSCve26946.
How severe is CVE-2018-0138?: CVE-2018-0138 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2018-0138 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-0138?: CVE-2018-0138 primarily affects Cisco Firepower Threat Defense. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-0138?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-0138 published?: CVE-2018-0138 was published on 2018-02-08 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:cisco:firepower_threat_defense:6.1.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_threat_defense:6.2.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_threat_defense:6.2.2:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_threat_defense:6.2.3:*:*:*:*:*:*:*

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