CVE-2018-0491
A use-after-free issue was discovered in Tor 0.3.2.x before 0.3.2.10. It allows remote attackers...
A use-after-free issue was discovered in Tor 0.3.2.x before 0.3.2.10. It allows remote attackers to cause a denial of service (relay crash) because the KIST implementation allows a channel to be added more than once in the pending list.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
A use-after-free issue was discovered in Tor 0.3.2.x before 0.3.2.10. It allows remote attackers to cause a denial of service (relay crash) because the KIST implementation allows a channel to be added more than once in the pending list.
- Record
CVE-2018-0491- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-416
- Updated
- 2026-11-02
CVE List No score
A use-after-free issue was discovered in Tor 0.3.2.x before 0.3.2.10. It allows remote attackers to cause a denial of service (relay crash) because the KIST implementation allows a channel to be added more than once in the pending list.
- Record
CVE-2018-0491- Updated
- 2026-11-02
EUVDEUVD-2018-1314 No score
A use-after-free issue was discovered in Tor 0.3.2.x before 0.3.2.10. It allows remote attackers to cause a denial of service (relay crash) because the KIST implementation allows a channel to be added more than once in the pending list.
- Record
EUVD-2018-1314- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-8wr4-7fjq-4qxw
A use-after-free issue was discovered in Tor 0.3.2.x before 0.3.2.10. It allows remote attackers...
A use-after-free issue was discovered in Tor 0.3.2.x before 0.3.2.10. It allows remote attackers to cause a denial of service (relay crash) because the KIST implementation allows a channel to be added more than once in the pending list.
- Record
GHSA-8wr4-7fjq-4qxw- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-416
- Updated
- 2026-11-02
OSV
A use-after-free issue was discovered in Tor 0.3.2.x before 0.3.2.10. It allows remote attackers to cause a denial of service (relay crash) because the KIST implementation allows a channel to be added more than once in the pending list.
- Record
CVE-2018-0491- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2018-0491
A use-after-free issue was discovered in Tor 0.3.2.x before 0.3.2.10. It allows remote attackers to cause a denial of service (relay crash) because the KIST implementation allows a channel to be added more than once in the pending list.
- Record
DEBIAN-CVE-2018-0491- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Show 5 moreShow less
OSVUBUNTU-CVE-2018-0491
A use-after-free issue was discovered in Tor 0.3.2.x before 0.3.2.10. It allows remote attackers to cause a denial of service (relay crash) because the KIST implementation allows a channel to be added more than once in the pending list.
- Record
UBUNTU-CVE-2018-0491- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVMGASA-2018-0161 No score
Updated tor packages fix security vulnerabilities
A protocol-list handling bug that could be used to remotely crash directory authorities with a null-pointer exception (CVE-2018-0490).
A bug can be remotely triggered in order to crash relays with a use-after-free pattern (CVE-2018-0491).
- Record
MGASA-2018-0161- Updated
- 2026-11-02
OSVopenSUSE-SU-2018:0614-1 No score
Security update for tor
This update for tor to version 0.3.2.10 fixes security issues and bugs.
The following vulnerabilities were fixed:
- CVE-2018-0490: remote crash vulnerability against directory authorities (boo#1083845, TROVE-2018-001)
- CVE-2018-0491: remote relay crash (boo#1083846, TROVE-2018-002)
This new upstream stable version also contains a new system for improved resistance to DoS attacks against relays and various other bug fixes.
- Record
openSUSE-SU-2018:0614-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2018:0620-1 No score
Security update for tor
This update for tor to version 0.3.2.10 fixes security issues and bugs.
The following vulnerabilities were fixed:
- CVE-2018-0490: remote crash vulnerability against directory authorities (boo#1083845, TROVE-2018-001)
- CVE-2018-0491: remote relay crash (boo#1083846, TROVE-2018-002)
This new upstream stable version also contains a new system for improved resistance to DoS attacks against relays and various other bug fixes.
- Record
openSUSE-SU-2018:0620-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2024:11469-1 No score
tor-0.4.6.7-2.2 on GA media
These are all security issues fixed in the tor-0.4.6.7-2.2 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:11469-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
torDebian:12 |
before 0.3.2.10-1 | 0.3.2.10-1 |
torDebian:13 |
before 0.3.2.10-1 | 0.3.2.10-1 |
torDebian:14 |
before 0.3.2.10-1 | 0.3.2.10-1 |
torMageia:6 From an advisory covering 2 CVEs |
before 0.2.9.15-1.mga6 | 0.2.9.15-1.mga6 |
torUbuntu:18.04:LTS |
before 0.3.2.10-1, plus listed versions 0.3.0.10-10.3.1.8-20.3.1.9-10.3.2.9-10.3.2.9-1build1 |
0.3.2.10-1 |
torSUSE:Package Hub 12 From an advisory covering 2 CVEs |
before 0.3.2.10-14.1 | 0.3.2.10-14.1 |
toropenSUSE:Tumbleweed From an advisory covering 22 CVEs |
before 0.4.6.7-2.2 | 0.4.6.7-2.2 |
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Exploit-DB | Tor Browser < 0.3.2.10 - Use After Free (PoC) | 2018-07-09 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| aliases | EUVD | |
| first indexed | CVE List, Exploit-DB, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2018-0491 is a high vulnerability (CVSS 7.5) in Torproject Tor, published March 5, 2018. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 14.8%, the 96th percentile. Fixed in tor 0.3.2.10-1.
References
trac.torproject.org/projects/tor/ticket/24700
blog.torproject.org/new-stable-tor-releases-security-fixes-and-dos-prevention-03210-03110-02915
exploit-db.com/exploits/44994
nvd.nist.gov/vuln/detail/CVE-2018-0491
github.com/advisories/GHSA-8wr4-7fjq-4qxw
Show 29 moreShow less
security-tracker.debian.org/tracker/CVE-2018-0491
advisories.mageia.org/MGASA-2018-0161.html
bugs.mageia.org/show_bug.cgi?id=22690
ubuntu.com/security/CVE-2018-0491
cve.org/CVERecord?id=CVE-2018-0491
bugzilla.suse.com/1083845
suse.com/security/cve/CVE-2018-0490