"vulnerable link" is a perfectly acceptable phrase in written English.
You can use it when referring to something that is susceptible to exploitation or harm, or a potential point of failure. For example, "The large number of components in the system creates several vulnerable links."
A system is only as secure as its most vulnerable link, and becomes geometrically less secure with each additional vulnerability.
In the complex chain of plants and equipment that move oil from the Middle East, oil tankers are in many ways the most vulnerable link.
The most vulnerable link in the drug chain involves light aircraft that ferry processed cocaine from laboratories in the Llanos to the coasts.
"It's very clear that over the years the military-to-military relationship has been the most vulnerable link between the two countries in times of stress," said David M. Finkelstein, an analyst for the CNA Corporation's Center for Strategic Studies who has studied the exchanges.
[C1.] Merchants Seen as Vulnerable Link to Data Breaches While banks and payment processors have been targets in the largest cases of data theft, security specialists say the payment system's most vulnerable points may be the millions of merchants where cards are accepted.
This is done based on the target signal-to-noise-plus-interference ratio (SINR) and tolerable interference of the vulnerable link.
They must then divine which medications are most likely to attack those cancers along vulnerable links in their progression, and test their effectiveness.
Pope Benedict XVI, made great strides in helping bring awareness to climate change and the impacts it will have on the poor and vulnerable, linking climate change to food insecurity and water scarcity and calling for action.
These range from help with the financing and construction of a huge new port on Pakistan's southern coast, projects to improve the currently vulnerable road link than runs over the Himalayas, assistance with railways and enormous hydroelectric schemes such as the controversial dam being built in the foothills of the mountains near the disputed de facto border with India in Kashmir.
It follows a November announcement from Canada and its Commonwealth partners committing $10 billion to climate change adaptation for vulnerable countries (link).
Listen to UNICEF spokesman Patrick McCormick on protecting Haiti's "most vulnerable" (external link, opens in a new window).
