Tor before 0.2.4.23 and 0.2.5 before 0.2.5.6-alpha maintains a circuit after an inbound RELAY_EARLY cell is received by a client, which make
Tor before 0.2.4.23 and 0.2.5 before 0.2.5.6-alpha maintains a circuit after an inbound RELAY_EARLY cell is received by a client, which makes it easier for remote attackers to conduct traffic-confirmation attacks by using the pattern of RELAY and RELAY_EARLY cells as a means of communicating information about hidden service names.
- Published
- Jul 30, 2014
- Updated
- Jun 16, 2026
- EPSS
- 2.1% · 81th percentile
- CWE
- —
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Report tools
Action score
24
Monitor
Low priority for now.
- CVSS
- 23 / 40 · 5.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.1%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| torproject | tor | cpe:2.3:a:torproject:tor |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- torproject torup to 0.2.4.22 inclusive
- torproject tor0.0.2
- torproject tor0.0.3
- torproject tor0.0.4
- torproject tor0.0.5
- torproject tor0.0.6
- torproject tor0.0.6.1
- torproject tor0.0.6.2
- torproject tor0.0.7
- torproject tor0.0.7.1
- torproject tor0.0.7.2
- torproject tor0.0.7.3
- torproject tor0.0.8.1
- torproject tor0.0.9.1
- torproject tor0.0.9.10
- torproject tor0.0.9.2
- torproject tor0.0.9.3
- torproject tor0.0.9.4
- torproject tor0.0.9.5
- torproject tor0.0.9.6
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | tor | before 0.2.4.23-1 | 0.2.4.23-1 |
| Debian:6.0 | tor | before 0.2.4.23-1~deb6u1 | 0.2.4.23-1~deb6u1 |
| Debian:7 | tor | before 0.2.4.23-1~deb7u1 | 0.2.4.23-1~deb7u1 |
| openSUSE:Tumbleweed | tor | before 0.2.8.11-1.1 | 0.2.8.11-1.1 |
Same product
torproject: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-77642tor before 0.4.9.9 was prone to an out-of-bounds write when parsing a consensus or detached signature with unexpected signature digest type37Monitor
- CVE-2026-77638Tor before 0.4.9.11 is prone to a race condition where in just the right circumstances a rendezvous point could man-in-the-middle (impersona36Monitor
- CVE-2026-44603Tor before 0.4.9.7 has an out-of-bounds read by one byte via a malformed BEGIN cell, aka TROVE-2026-007.36Monitor
- CVE-2026-44597Tor before 0.4.9.7 has an out-of-bounds read when an END, a TRUNCATE, or a TRUNCATED cell lacks a reason in its payload, aka TROVE-2026-011.36Monitor
- CVE-2018-0491A use-after-free issue was discovered in Tor 0.3.2.x before 0.3.2.10.34Monitor
- CVE-2026-77641tor before 0.4.9.9 was prone to a NULL write after free when sending a CONFLUX_SWITCH cell fails.32Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:tor | 0.2.4.23-1 · Debian:12 | Package registry (OSV) |
| opensuse:tor | 0.2.8.11-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.
Technical details
Attack conditions
If successful
- Confidentiality
- P · data can be read
- Integrity
- P · data or configuration can be modified
- Availability
- none
- Attack complexity
- M
- Confidentiality impact
- P
- Integrity impact
- P
- Availability impact
- None
Weakness class (CWE)
—
CVSS vector
AV:N/AC:M/Au:N/C:P/I:P/A:N
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
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References
- secunia.com/advisories/60084
- secunia.com/advisories/60647
- blog.torproject.org/blog/tor-security-advisory-relay-early-traffic-confirmation-attack
- lists.torproject.org/pipermail/tor-announce/2014-July/000093.html
- lists.torproject.org/pipermail/tor-announce/2014-July/000094.html
- lists.torproject.org/pipermail/tor-talk/2014-July/034180.html
- trac.torproject.org/projects/tor/ticket/1038
Vendor advisories and official records. Exploit/PoC links are deliberately left out.