How severe is CVE-2007-5638?

CVE-2007-5638 has a CVSS 2.0 base score of 4.3, rated medium severity.

Is CVE-2007-5638 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2007-5638?

CVE-2007-5638 primarily affects Nortel Business Communications Manager. In total, 16 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2007-5638?

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

When was CVE-2007-5638 published?

CVE-2007-5638 was published on 2007-10-23 and last updated on 2026-06-16.

CVE-2007-5638

CVE-2007-5638 is a medium-severity vulnerability in Nortel Business Communications Manager with a CVSS 2.0 base score of 4.3. 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-200.

Key facts

Severity: Medium (CVSS 2.0 base score 4.3)
EPSS exploit prediction: 1% (71st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Nortel Business Communications Manager
Published: 2007-10-23
Last modified: 2026-06-16

Description

The Nortel UNIStim IP Softphone 2050, IP Phone 1140E, and additional Nortel products from the IP Phone, Business Communications Manager (BCM), and other product lines, use only 65536 different values in the 32-bit ID number field of an RUDP datagram, which makes it easier for remote attackers to guess the RUDP ID and spoof messages. NOTE: this can be leveraged for an eavesdropping attack by sending many Open Audio Stream messages.

Frequently asked questions

What is CVE-2007-5638?: The Nortel UNIStim IP Softphone 2050, IP Phone 1140E, and additional Nortel products from the IP Phone, Business Communications Manager (BCM), and other product lines, use only 65536 different values in the 32-bit ID number field of an RUDP datagram, which makes it easier for remote attackers to guess the RUDP ID and spoof messages. NOTE: this can be leveraged for an eavesdropping attack by sending many Open Audio Stream messages.
How severe is CVE-2007-5638?: CVE-2007-5638 has a CVSS 2.0 base score of 4.3, rated medium severity.
Is CVE-2007-5638 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2007-5638?: CVE-2007-5638 primarily affects Nortel Business Communications Manager. In total, 16 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2007-5638?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2007-5638 published?: CVE-2007-5638 was published on 2007-10-23 and last updated on 2026-06-16.

References

Affected products (16)

cpe:2.3:a:nortel:business_communications_manager:50:*:*:*:*:*:*:*
cpe:2.3:a:nortel:business_communications_manager:50a:*:*:*:*:*:*:*
cpe:2.3:a:nortel:business_communications_manager:50e:*:*:*:*:*:*:*
cpe:2.3:a:nortel:business_communications_manager:200:*:*:*:*:*:*:*
cpe:2.3:a:nortel:business_communications_manager:400:*:*:*:*:*:*:*
cpe:2.3:a:nortel:business_communications_manager:1000:*:*:*:*:*:*:*
cpe:2.3:a:nortel:business_communications_manager:srg50:*:*:*:*:*:*:*
cpe:2.3:a:nortel:business_communications_manager:srg200:*:*:*:*:*:*:*
cpe:2.3:a:nortel:centrex_ip_client_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:nortel:centrex_ip_element_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:nortel:meridian_option_11c:*:*:*:*:*:*:*:*
cpe:2.3:a:nortel:meridian_option_51c:*:*:*:*:*:*:*:*
cpe:2.3:a:nortel:meridian_option_61c:*:*:*:*:*:*:*:*
cpe:2.3:a:nortel:meridian_option_81c:*:*:*:*:*:*:*:*
cpe:2.3:a:nortel:meridian_sl100:cs2100:*:*:*:*:*:*:*
cpe:2.3:a:nortel:mobile_voice_client_2050:*:*:*:*:*:*:*:*

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