CVE-2017-16541

CVE-2017-16541 is a medium-severity vulnerability in Torproject Tor with a CVSS 3.x base score of 6.5. 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-200.

Key facts

• Severity: Medium (CVSS 3.x base score 6.5)
• CVSS v2: 4.3
• EPSS exploit prediction: 4% (88th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-200
• Affected product: Torproject Tor
• Published: 2017-11-04
• Last modified: 2026-06-17

Description

Tor Browser before 7.0.9 on macOS and Linux allows remote attackers to bypass the intended anonymity feature and discover a client IP address via vectors involving a crafted web site that leverages file:// mishandling in Firefox, aka TorMoil. NOTE: Tails is unaffected.

Frequently asked questions

What is CVE-2017-16541?

Tor Browser before 7.0.9 on macOS and Linux allows remote attackers to bypass the intended anonymity feature and discover a client IP address via vectors involving a crafted web site that leverages file:// mishandling in Firefox, aka TorMoil. NOTE: Tails is unaffected.

How severe is CVE-2017-16541?

CVE-2017-16541 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2017-16541 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-16541?

CVE-2017-16541 primarily affects Torproject Tor. In total, 16 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2017-16541?

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

When was CVE-2017-16541 published?

CVE-2017-16541 was published on 2017-11-04 and last updated on 2026-06-17.

References

• http://www.securityfocus.com/bid/101665
• http://www.securitytracker.com/id/1041610
• https://access.redhat.com/errata/RHSA-2018:2692
• https://access.redhat.com/errata/RHSA-2018:2693
• https://access.redhat.com/errata/RHSA-2018:3403
• https://access.redhat.com/errata/RHSA-2018:3458
• https://blog.torproject.org/tor-browser-709-released
• https://bugzilla.mozilla.org/show_bug.cgi?id=1412081
• https://lists.debian.org/debian-lts-announce/2018/11/msg00011.html
• https://security.gentoo.org/glsa/201810-01
• https://security.gentoo.org/glsa/201811-13
• https://trac.torproject.org/projects/tor/ticket/24052
• https://www.bleepingcomputer.com/news/security/tormoil-vulnerability-leaks-real-ip-address-from-tor-browser-users/
• https://www.debian.org/security/2018/dsa-4327
• https://www.wearesegment.com/research/tormoil-torbrowser-unspecified-critical-security-vulnerability/

Affected products (16)

• cpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_desktop:6.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_eus:7.5:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_eus:7.6:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_eus:7.7:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_server:6.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_server_aus:7.6:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_server_aus:7.7:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_server_tus:7.6:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_server_tus:7.7:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_workstation:6.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*
• cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
• cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

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