CVE-2023-37457: Asterisk's PJSIP_HEADER dialplan function can overwrite memory/cause crash when using 'update'

Severity: high (CVSS 8.2 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-12-14 · updated 2026-06-17
Weakness: CWE-120

Description

Asterisk is an open source private branch exchange and telephony toolkit. In Asterisk versions 18.20.0 and prior, 20.5.0 and prior, and 21.0.0; as well as ceritifed-asterisk 18.9-cert5 and prior, the 'update' functionality of the PJSIP_HEADER dialplan function can exceed the available buffer space for storing the new value of a header. By doing so this can overwrite memory or cause a crash. This is not externally exploitable, unless dialplan is explicitly written to update a header based on data from an outside source. If the 'update' functionality is not used the vulnerability does not occur. A patch is available at commit a1ca0268254374b515fa5992f01340f7717113fa.

Affected products

Digium Asterisk: through 18.20.0; from 19.0.0 through 20.5.0; 21.0.0
Sangoma Certified Asterisk: 13.13.0, 13.13.0-cert1, 13.13.0-cert1-rc1, 13.13.0-cert1-rc2, 13.13.0-cert1-rc3, 13.13.0-cert1-rc4 (+22)

References

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