CVE-2021-34758 | Cisco TelePresence Collaboration Endpoint and RoomOS Software Denial of Service Vulnerability

A vulnerability in the memory management of Cisco TelePresence Collaboration Endpoint (CE) Software and Cisco RoomOS Software could allow an authenticated, local attacker to corrupt a shared memory segment, resulting in a denial of service (DoS) condition. This vulnerability is due to insufficient access controls to a shared memory resource. An attacker could exploit this vulnerability by corrupting a shared memory segment on an affected device. A successful exploit could allow the attacker to cause the device to reload. The device will recover from the corruption upon reboot.

Published: 2021-10-06 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-34758 is rated Low Risk (20.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.18%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-34758

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.11% 0.18% +0.07%
2 2025-11-21 0.05% 0.11% +0.06%
3 2025-11-18 0.05%

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-34758

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.4 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
1.8 2.5 [email protected]
3.3 3.1 LOW
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
1.8 1.4 [email protected]
2.1 2.0 LOW
AV:L/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
3.9 2.9 [email protected]

Weakness enumeration for CVE-2021-34758

Affected software / configurations for CVE-2021-34758

Vendor Product Version Raw CPE
cisco telepresence_collaboration_endpoint < 10.7.2 cpe:2.3:a:cisco:telepresence_collaboration_endpoint:*:*:*:*:*:*:*:*
cisco roomos < 10.7.1.2 cpe:2.3:o:cisco:roomos:*:*:*:*:*:*:*:*

References for CVE-2021-34758

cvelogic Threat Intelligence