CVE-2024-39920
The TCP protocol in RFC 9293 has a timing side channel that makes it easier for remote attackers...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
4.3
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.
- Record
CVE-2024-39920- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-1255
- Updated
- 2026-11-02
EUVDEUVD-2024-38300
4.3
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.
- Record
EUVD-2024-38300- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-796p-jr7h-8vmq
4.3
The TCP protocol in RFC 9293 has a timing side channel that makes it easier for remote attackers...
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.
- Record
GHSA-796p-jr7h-8vmq- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-1255
- Updated
- 2026-11-02
NVD
4.3
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.
- Record
CVE-2024-39920- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-1255
- Updated
- 2026-11-02
OSVBELL-CVE-2024-39920
4.3
CVE-2024-39920 does not affect BellSoft software
- Record
BELL-CVE-2024-39920- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2024-39920 is a medium vulnerability (CVSS 4.3) in Ietf Tcp, published July 3, 2024. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.57%, the 47th percentile. No source names a fixed version.
References
snailload.com
snailload.com/snailload.pdf
github.com/IAIK/SnailLoad
rfc-editor.org/rfc/rfc9293.txt
tugraz.at/en/tu-graz/services/news-stories/tu-graz-news/singleview/article/neue-sicherheitsluecke-erlaubt-ueberwachung-besuchter-websites-und-angesehener-videos
twitter.com/tugraz/status/1805272833322299412