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CVE-2024-7589· NVD / CVE Program· CNA freebsd

OpenSSH pre-authentication async signal safety issue

Noroxi assessment

Priority: Monitor (action score 33/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 2% (FIRST EPSS); higher than 80.7% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: FreeBSD FreeBSD p3, p5, p9.

Low priority for now. Upgrade to FreeBSD FreeBSD p3, p5, p9 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A signal handler in sshd(8) may call a logging function that is not async-signal-safe. The signal handler is invoked when a client does not authenticate within the LoginGraceTime seconds (120 by default). This signal handler executes in the context of the sshd(8)'s privileged code, which is not sandboxed and runs with full root privileges. This issue is another instance of the problem in CVE-2024-6387 addressed by FreeBSD-SA-24:04.openssh. The faulty code in this case is from the integration of blacklistd in OpenSSH in FreeBSD. As a result of calling functions that are not async-signal-safe in the privileged sshd(8) context, a race condition exists that a determined attacker may be able to exploit to allow an unauthenticated remote code execution as root.

HighCVSS 8.1 · v3.1—No exploit Fix available
Published
Aug 12, 2024
Updated
Jun 17, 2026
EPSS
2.0% · 80th percentile

Report tools

JSON

Action score

33

Monitor

Low priority for now.

CVSS
32 / 40 · 8.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 2.0%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2024-7589

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
freebsdfreebsd

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • freebsd freebsdbefore 13.0
  • freebsd freebsd13.1 and later · before 13.3
  • freebsd freebsd13.3
  • freebsd freebsd14.0
  • freebsd freebsd14.1

Versions reported by the vendor

Affected version ranges reported by the assigning authority (freebsd). Independent of NVD's CPE analysis and usually ahead of it.

  • FreeBSD FreeBSD

    • 14.1-RELEASE and later · before p3affected · release
    • 14.0-RELEASE and later · before p9affected · release
    • 13.3-RELEASE and later · before p5affected · release

Same product

freebsd: all records

Other highest-scoring records for the same primary product.

  • CVE-2006-0900nfsd in FreeBSD 6.0 kernel allows remote attackers to cause a denial of service via a crafted NFS mount request, as demonstrated by the Prot
    51Plan
  • CVE-2018-17157In FreeBSD before 11.2-STABLE(r340854) and 11.2-RELEASE-p5, an integer overflow error when handling opcodes can cause memory corruption by s
    46Plan
  • CVE-2010-1938Off-by-one error in the __opiereadrec function in readrec.c in libopie in OPIE 2.4.1-test1 and earlier, as used on FreeBSD 6.4 through 8.1-P
    44Plan
  • CVE-2006-4304Buffer overflow in the sppp driver in FreeBSD 4.11 through 6.1, NetBSD 2.0 through 4.0 beta before 20060823, and OpenBSD 3.8 and 3.9 before
    44Plan
  • CVE-2020-7457In FreeBSD 12.1-STABLE before r359565, 12.1-RELEASE before p7, 11.4-STABLE before r362975, 11.4-RELEASE before p1, and 11.3-RELEASE before p
    42Plan
  • CVE-2008-2427Stack-based buffer overflow in NConvert 4.92, GFL SDK 2.82, and XnView 1.93.6 on Windows and 1.70 on Linux and FreeBSD allows user-assisted
    42Plan

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
FreeBSD FreeBSDp3Vendor (CNA)
FreeBSD FreeBSDp5Vendor (CNA)
FreeBSD FreeBSDp9Vendor (CNA)

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.

EPSS, last 120 days

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 researchers

Finders, 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

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

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.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records