CVE-2024-53704

From Exploited flaws, HARD’s guide to the flaws being used in attacks · Checked
This article is about a flaw in SonicWall SonicOS. For every flaw being used in attacks, see Exploited flaws; for SonicWall’s, see SonicWall flaws being used in attacks.

CVE-2024-53704 is a security flaw in SonicWall SonicOS, SonicWall’s firewall and remote-access equipment. Attackers can get into SonicWall SonicOS without a valid password. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 18 Feb 2025, and says ransomware gangs have used it.[1]

SonicWall SonicOS is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. SonicWall has published a fix or advice.

Description

CISA calls it an SSLVPN improper authentication in SonicWall SonicOS. In its words: “SonicWall SonicOS contains an improper authentication vulnerability in the SSLVPN authentication mechanism that allows a remote attacker to bypass authentication.”[1]

The underlying weakness is improper authentication (CWE-287), in MITRE’s list of common software weaknesses.[2]

It scores 9.8 out of 10 on the Common Vulnerability Scoring System, which rates it critical, scored by NVD using CVSS 3.1.[2]

Affected versions

NVD’s record doesn’t list version ranges for it; SonicWall’s advisory has them[3]. CISA names the product as SonicWall SonicOS.

Most families won’t have SonicWall SonicOS; it’s for whoever looks after IT at work.

Exploitation

CISA added it to its catalog of known exploited vulnerabilities on 18 Feb 2025, 40 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 11 Mar 2025 to fix it.[1] CISA says ransomware gangs have used it.

FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 95%. That’s in the top 1% of the flaws it scores.[4]

CISA assesses it as automatable: attackers can run it against many targets at once.

CISA doesn’t say who was attacked, or how.

Fix

SonicWall has published a fix or advice.[3] CISA’s required action: “Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.”[1]

  1. Check whether you use it.SonicWall SonicOS is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
  2. Send this page to your IT person.Ask them to confirm it’s fixed, or not in use. CISA gave US government agencies until 11 Mar 2025 to fix it.
  3. If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.

You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.

Timeline

DateEvent
The flaw is made public in the National Vulnerability Database, with a severity score of 9.8.[2]
CISA adds it to its catalog of flaws known to be used in attacks, noting that ransomware gangs have used it.[1]
CISA’s deadline for US government agencies to fix it.[1]
FIRST puts the odds of it being used in attacks in the next 30 days at 95%.[4]

See also

Other SonicWall SonicOS flaws

Other SonicWall flaws

  • CVE-2026-83549, SonicWall SMA1000 Appliances: OS command injection ·
  • CVE-2026-83548, SonicWall SMA1000 Appliances: server-side request forgery ·
  • CVE-2026-15410, SonicWall SMA1000 Appliances: code injection ·
  • CVE-2026-15409, SonicWall SMA1000 Appliances: server-side request forgery ·
  • CVE-2025-40602, SonicWall SMA1000 appliance: sMA1000 missing authorization ·

Other improper authentication flaws

Added the same day

  • CVE-2025-0108, Palo Alto Networks PAN-OS: authentication bypass ·

Every SonicWall flaw on CISA’s list · Everything added in February 2025

References

  1. ^ Cybersecurity and Infrastructure Security Agency. “SonicWall SonicOS SSLVPN Improper Authentication Vulnerability”. Known Exploited Vulnerabilities Catalog, added 18 Feb 2025.
  2. ^ National Institute of Standards and Technology. “CVE-2024-53704 Detail”. National Vulnerability Database, published 9 Jan 2025.
  3. ^ SonicWall. Advisories and fixes: psirt.global.sonicwall.com.
  4. ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.953, percentile 99.9, 31 Oct 2026.
  5. CVE Program. “CVE-2024-53704”. The official CVE record.

This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.