How severe is CVE-2009-4831?

CVE-2009-4831 has a CVSS 2.0 base score of 5.8, rated medium severity.

Is CVE-2009-4831 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-4831?

CVE-2009-4831 affects Cerulean Studios Trillian. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2009-4831?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2009-4831 published?

CVE-2009-4831 was published on 2010-04-29 and last updated on 2026-06-16.

CVE-2009-4831

CVE-2009-4831 is a medium-severity vulnerability in Cerulean Studios Trillian with a CVSS 2.0 base score of 5.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-295.

Key facts

Severity: Medium (CVSS 2.0 base score 5.8)
EPSS exploit prediction: 1% (69th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-295
Affected product: Cerulean Studios Trillian
Published: 2010-04-29
Last modified: 2026-06-16

Description

Cerulean Studios Trillian 3.1 Basic does not check SSL certificates during MSN authentication, which allows remote attackers to obtain MSN credentials via a man-in-the-middle attack with a spoofed SSL certificate.

Frequently asked questions

What is CVE-2009-4831?: Cerulean Studios Trillian 3.1 Basic does not check SSL certificates during MSN authentication, which allows remote attackers to obtain MSN credentials via a man-in-the-middle attack with a spoofed SSL certificate.
How severe is CVE-2009-4831?: CVE-2009-4831 has a CVSS 2.0 base score of 5.8, rated medium severity.
Is CVE-2009-4831 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-4831?: CVE-2009-4831 affects Cerulean Studios Trillian. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2009-4831?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-4831 published?: CVE-2009-4831 was published on 2010-04-29 and last updated on 2026-06-16.

References

Affected products (1)

cpe:2.3:a:cerulean_studios:trillian:3.1:*:*:*:basic:*:*:*

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