CVE-2015-2928

The Hidden Service (HS) server implementation in Tor before 0.2.4.27, 0.2.5.x before 0.2.5.12, and 0.2.6.x before 0.2.6.7 allows remote attackers to cause a denial of service (assertion failure and daemon exit) via unspecified vectors.

Published: 2020-01-24 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2015-2928 is rated Moderate Risk (53.4/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.72%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2015-2928

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-03-30 1.85% 0.72% -1.13%
2 2025-03-29 0.72% 1.85% +1.13%
3 2025-03-17 0.72%

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2015-2928

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
10.0 2.9 [email protected]

Weakness enumeration for CVE-2015-2928

OS Trackers for CVE-2015-2928

vendor priority summary link
debian not yet assigned CVE-2015-2928 not yet assigned priority: Debian including 1 source packages (tor), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2015-2928
gentoo normal CVE-2015-2928: 1 GLSA(s) (201507-02), 1 atom(s) (net-misc/tor); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2015-2928
ubuntu medium CVE-2015-2928 medium priority: Ubuntu including 1 source packages (tor), 10 status rows across 10 suites (lucid, precise, trusty, upstream, utopic, vivid, wily, xenial, yakkety, zesty): not-affected 4, released 3, ignored 2, DNE 1. https://ubuntu.com/security/CVE-2015-2928

Affected software / configurations for CVE-2015-2928

Vendor Product Version Raw CPE
torproject tor < 0.2.4.27 cpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:*
torproject tor >= 0.2.5.1, < 0.2.5.12 cpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:*
torproject tor >= 0.2.6.1, < 0.2.6.7 cpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:*

References for CVE-2015-2928

cvelogic Threat Intelligence