CVE-2011-2778

CVE-2011-2778 is a high-severity vulnerability in Tor with a CVSS 2.0 base score of 7.6. 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-119.

Key facts

Description

Multiple heap-based buffer overflows in Tor before 0.2.2.35 allow remote attackers to cause a denial of service (memory corruption) or possibly execute arbitrary code by (1) establishing a SOCKS connection to SocksPort or (2) leveraging a SOCKS proxy configuration.

Frequently asked questions

What is CVE-2011-2778?
Multiple heap-based buffer overflows in Tor before 0.2.2.35 allow remote attackers to cause a denial of service (memory corruption) or possibly execute arbitrary code by (1) establishing a SOCKS connection to SocksPort or (2) leveraging a SOCKS proxy configuration.
How severe is CVE-2011-2778?
CVE-2011-2778 has a CVSS 2.0 base score of 7.6, rated high severity.
Is CVE-2011-2778 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2011-2778?
CVE-2011-2778 primarily affects Tor. In total, 230 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2011-2778?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2011-2778 published?
CVE-2011-2778 was published on 2011-12-23 and last updated on 2026-06-16.

References

Affected products (230)

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