CVE-2005-2643

CVE-2005-2643 is a medium-severity vulnerability in Tor with a CVSS 2.0 base score of 5.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

Tor 0.1.0.13 and earlier, and experimental versions 0.1.1.4-alpha and earlier, does not reject certain weak keys when using ephemeral Diffie-Hellman (DH) handshakes, which allows malicious Tor servers to obtain the keys that a client uses for other systems in the circuit.

Frequently asked questions

What is CVE-2005-2643?
Tor 0.1.0.13 and earlier, and experimental versions 0.1.1.4-alpha and earlier, does not reject certain weak keys when using ephemeral Diffie-Hellman (DH) handshakes, which allows malicious Tor servers to obtain the keys that a client uses for other systems in the circuit.
How severe is CVE-2005-2643?
CVE-2005-2643 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-2005-2643 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (66th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2005-2643?
CVE-2005-2643 primarily affects Tor. In total, 27 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2005-2643?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2005-2643 published?
CVE-2005-2643 was published on 2005-08-23 and last updated on 2026-06-16.

References

Affected products (27)

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