CVE-2024-39920

The TCP protocol in RFC 9293 has a timing side channel that makes it easier for remote attackers to infer the content of one TCP connection from a client system (to any server), when that client system is concurrently obtaining TCP data at a slow rate from an attacker-controlled server, aka the "SnailLoad" issue. For example, the attack can begin by measuring RTTs via the TCP segments whose role is to provide an ACK control bit and an Acknowledgment Number.

Published: 2024-07-03 Last update: 2026-04-15 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-39920 is rated Low Risk (23.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.06%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2024-39920

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 2025-11-21 0.20% 0.06% -0.15%
2 2025-11-18 0.06% 0.20% +0.15%
3 2025-08-14 — 0.06% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-39920

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 3.1 MEDIUM
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 1.4 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2024-39920

OS Trackers for CVE-2024-39920

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2024-39920
suse medium CVE-2024-39920 severity moderate: SUSE including 26 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 288 product×package rows across 57 product lines (SUSE Enterprise Storage 7.1, SUSE Linux Enterprise High Availability Extension 12 SP5, … (57 product lines)): Known Not Affected 288. https://www.suse.com/security/cve/CVE-2024-39920/

Affected software / configurations for CVE-2024-39920

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2024-39920

cvelogic Threat Intelligence