CVE-2019-5101

CVE-2019-5101 is a medium-severity vulnerability in Openwrt with a CVSS 3.x base score of 4.0. 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

Description

An exploitable information leak vulnerability exists in the ustream-ssl library of OpenWrt, versions 18.06.4 and 15.05.1. When connecting to a remote server, the server's SSL certificate is checked but no action is taken when the certificate is invalid. An attacker could exploit this behavior by performing a man-in-the-middle attack, providing any certificate, leading to the theft of all the data sent by the client during the first request.An exploitable information leak vulnerability exists in the ustream-ssl library of OpenWrt, versions 18.06.4 and 15.05.1. When connecting to a remote server, the server's SSL certificate is checked but no action is taken when the certificate is invalid. An attacker could exploit this behavior by performing a man-in-the-middle attack, providing any certificate, leading to the theft of all the data sent by the client during the first request. After an SSL connection is initialized via _ustream_ssl_init, and after any data (e.g. the client's HTTP request) is written to the stream using ustream_printf, the code eventually enters the function _ustream_ssl_poll, which is used to dispatch the read/write events

Frequently asked questions

What is CVE-2019-5101?
An exploitable information leak vulnerability exists in the ustream-ssl library of OpenWrt, versions 18.06.4 and 15.05.1. When connecting to a remote server, the server's SSL certificate is checked but no action is taken when the certificate is invalid. An attacker could exploit this behavior by performing a man-in-the-middle attack, providing any certificate, leading to the theft of all the data sent by the client during the first request.An exploitable information leak vulnerability exists in the ustream-ssl library of OpenWrt, versions 18.06.4 and 15.05.1. When connecting to a remote server, the server's SSL certificate is checked but no action is taken when the certificate is invalid. An attacker could exploit this behavior by performing a man-in-the-middle attack, providing any certificate, leading to the theft of all the data sent by the client during the first request. After an SSL connection is initialized via _ustream_ssl_init, and after any data (e.g. the client's HTTP request) is written to the stream using ustream_printf, the code eventually enters the function _ustream_ssl_poll, which is used to dispatch the read/write events
How severe is CVE-2019-5101?
CVE-2019-5101 has a CVSS 3.x base score of 4.0, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2019-5101 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-5101?
CVE-2019-5101 primarily affects Openwrt. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-5101?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2019-5101 published?
CVE-2019-5101 was published on 2019-11-18 and last updated on 2026-06-17.

References

Affected products (2)

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