TI-2015-02373 Aliases CVE-2015-2689 GHSA-7r2c-ch3m-w27x

Improper input validation in Tor

LOW 37CWE-20Published 2020-01-24 · Updated 2024-08-06

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: None · None · High
Fix status: Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA.

Summary

Tor before 0.2.4.26 and 0.2.5.x before 0.2.5.11 does not properly handle pending-connection resolve states during periods of high DNS load, which allows remote attackers to cause a denial of service (assertion failure and daemon exit) via crafted packets.

Why it matters now

EPSS 0.02185 82nd percentileScored 2026-11-07

Fix Fixed Tor (The Tor Project): 0.2.4.26, 0.2.5.11

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
The Tor Project	Tor	before 0.2.4.26; 0.2.5 to before 0.2.5.11	0.2.4.26, 0.2.5.11	Patch available	CNA

Tor VendorThe Tor Project Affected before 0.2.4.26; 0.2.5 to before 0.2.5.11 Fixed in 0.2.4.26, 0.2.5.11 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:torproject:tor::::::::	before 0.2.4.26; 0.2.5.1 to before 0.2.5.11	Vulnerable	torproject

cpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:* Versions before 0.2.4.26; 0.2.5.1 to before 0.2.5.11 Vulnerable ·torproject

Remediation

Fix · CNA Tor (The Tor Project) Fixed in 0.2.4.26, 0.2.5.11

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product

Red Hat

Timeline

2026-10-02 Threatist record created from CVE-2015-2689
2026-10-03 Alias added: GHSA-7r2c-ch3m-w27x

References

Patch 1

https://trac.torproject.org/projects/tor/ticket/14129

Advisory 1

https://lists.torproject.org/pipermail/tor-talk/2015-March/037281.html

TI-2017-06332 Use after free in Tor before 0.2.5.16, 0.2.6 through 0.2.8 before 0.2.8.17, 0.2.9 before… CVSS 3.0HIGH 8.1
TI-2017-06330 Memory corruption in Tor before 0.2.5.16, 0.2.6 through 0.2.8 before 0.2.8.17, 0.2.9… CVSS 3.0HIGH 7.5
TI-2017-06328 In Tor before 0.2.5.16, 0.2.6 through 0.2.8 before 0.2.8.17, 0.2.9 before 0.2.9.14, 0.3.0… CVSS 3.0HIGH 7.5
TI-2015-02372 Improper handling of exceptional conditions in Tor CVSS 3.1HIGH 7.5
TI-2017-06329 NULL pointer dereference in Tor before 0.2.5.16, 0.2.6 through 0.2.8 before 0.2.8.17… CVSS 3.0HIGH 7.5
TI-2015-02583 The Hidden Service (HS) server implementation in Tor before 0.2.4.27, 0.2.5.x before… CVSS 3.1HIGH 7.5

See all 8 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences