How severe is CVE-2021-30648?

CVE-2021-30648 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-30648 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-30648?

CVE-2021-30648 primarily affects Broadcom Symantec Proxysg. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-30648?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-30648 published?

CVE-2021-30648 was published on 2021-06-30 and last updated on 2026-06-17.

CVE-2021-30648

CVE-2021-30648 is a critical-severity vulnerability in Broadcom Symantec Proxysg with a CVSS 3.x base score of 9.8. 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-287.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 9.0
EPSS exploit prediction: 1% (70th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Broadcom Symantec Proxysg
Published: 2021-06-30
Last modified: 2026-06-17

Description

The Symantec Advanced Secure Gateway (ASG) and ProxySG web management consoles are susceptible to an authentication bypass vulnerability. An unauthenticated attacker can execute arbitrary CLI commands, view/modify the appliance configuration and policy, and shutdown/restart the appliance.

Frequently asked questions

What is CVE-2021-30648?: The Symantec Advanced Secure Gateway (ASG) and ProxySG web management consoles are susceptible to an authentication bypass vulnerability. An unauthenticated attacker can execute arbitrary CLI commands, view/modify the appliance configuration and policy, and shutdown/restart the appliance.
How severe is CVE-2021-30648?: CVE-2021-30648 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-30648 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-30648?: CVE-2021-30648 primarily affects Broadcom Symantec Proxysg. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-30648?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-30648 published?: CVE-2021-30648 was published on 2021-06-30 and last updated on 2026-06-17.

References

https://support.broadcom.com/security-advisory/content/security-advisories/0/SYMSA18331

Affected products (8)

cpe:2.3:a:broadcom:symantec_proxysg:*:*:*:*:*:*:*:*
cpe:2.3:o:broadcom:symantec_advanced_secure_gateway_s200-30_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:broadcom:symantec_advanced_secure_gateway_s200-40_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:broadcom:symantec_advanced_secure_gateway_s400-20_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:broadcom:symantec_advanced_secure_gateway_s400-30_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:broadcom:symantec_advanced_secure_gateway_s400-40_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:broadcom:symantec_advanced_secure_gateway_500-10_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:broadcom:symantec_advanced_secure_gateway_s500-20_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Broadcom Symantec Proxysg

CVE-2018-5241 — Critical (CVSS 9.8): Symantec Advanced Secure Gateway (ASG) 6.6 and 6.7, and ProxySG 6.5, 6.6, and 6.7 are susceptible to a SAML…
CVE-2016-9100 — High (CVSS 7.8): Symantec Advanced Secure Gateway (ASG) 6.6 prior to 6.6.5.13, ASG 6.7 prior to 6.7.3.1, ProxySG 6.5 prior to 6.5.10.6,…
CVE-2017-13677 — High (CVSS 7.5): Denial-of-service (DoS) vulnerability in the Symantec Advanced Secure Gateway (ASG) and ProxySG management consoles. A…
CVE-2016-9097 — High (CVSS 7.2): The Symantec Advanced Secure Gateway (ASG) 6.6 prior to 6.6.5.8, ProxySG 6.5 prior 6.5.10.6, ProxySG 6.6 prior to…
CVE-2016-10258 — Medium (CVSS 6.8): Unrestricted file upload vulnerability in the Symantec Advanced Secure Gateway (ASG) and ProxySG management consoles. A…
CVE-2019-18375 — Medium (CVSS 6.5): The ASG and ProxySG management consoles are susceptible to a session hijacking vulnerability. A remote attacker, with…

All CVEs affecting Broadcom Symantec Proxysg →

Other CWE-287 (Improper Authentication) vulnerabilities

CVE-2026-45480 — Critical (CVSS 10.0): Improper authentication in Azure Active Directory allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-46389 — Critical (CVSS 10.0): UDS Identity Config builds the Keycloak configuration image (realm, plugins, theme, truststore, JARs) consumed by UDS…
CVE-2026-10611 — Critical (CVSS 10.0): An authentication bypass vulnerability exists in MISP when LDAP mixed authentication is enabled with OTP enforcement.…
CVE-2026-47280 — Critical (CVSS 10.0): Improper authentication in Azure Resource Manager (ARM) allows an unauthorized attacker to elevate privileges over a…
CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
CVE-2026-20182 — Critical (CVSS 10.0): May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and…

Browse all CWE-287 (Improper Authentication) vulnerabilities →