Connect with us

Hi, what are you looking for?



SolarWinds Patches Serv-U Vulnerability Propagating Log4j Attacks

SolarWinds this week released patches for a Serv-U vulnerability that Microsoft says has been abused for the propagation of Log4j attacks.

SolarWinds this week released patches for a Serv-U vulnerability that Microsoft says has been abused for the propagation of Log4j attacks.

A multi-protocol file server, SolarWinds Serv-U can be used for sending/receiving files to/from systems on the network. Administrators can create accounts for users and give them permissions to access specific files and folders stored on the server or another network resource.

Tracked as CVE-2021-35247, this input validation bug allows an attacker to build a query based on a given input and then send the query over the network, without sanitization, according to Microsoft, whose researchers discovered the flaw.

“The Serv-U web login screen to LDAP authentication was allowing characters that were not sufficiently sanitized,” SolarWinds notes.

SolarWinds resolved the security error by updating the input mechanism, so that it performs additional validation and sanitization.

According to Microsoft, the vulnerability was identified while monitoring threats exploiting the Log4j vulnerabilities, when some attacks were observed being propagated via CVE-2021-35247.

Thus, the tech giant encourages organizations that use Serv-U to apply the available security updates as soon as possible.

Advertisement. Scroll to continue reading.

SolarWinds Serv-U 15.3 is the first version of the server to contain patches for the bug. Serv-U 15.2.5 and previous versions are vulnerable.

Related: SolarWinds Hackers Use New Malware in Recent Attacks

Related: Microsoft Says SolarWinds Serv-U Zero-Day Exploited by Chinese Group

Related: Microsoft Spots Multiple Nation-State APTs Exploiting Log4j Flaw

Related: Log4Shell Tools and Resources for Defenders – Continuously Updated

Written By

Ionut Arghire is an international correspondent for SecurityWeek.

Click to comment

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Join security experts as they discuss ZTNA’s untapped potential to both reduce cyber risk and empower the business.


Join Microsoft and Finite State for a webinar that will introduce a new strategy for securing the software supply chain.


Expert Insights

Related Content


Less than a week after announcing that it would suspended service indefinitely due to a conflict with an (at the time) unnamed security researcher...

Data Breaches

OpenAI has confirmed a ChatGPT data breach on the same day a security firm reported seeing the use of a component affected by an...

Risk Management

The supply chain threat is directly linked to attack surface management, but the supply chain must be known and understood before it can be...

IoT Security

A group of seven security researchers have discovered numerous vulnerabilities in vehicles from 16 car makers, including bugs that allowed them to control car...


Patch Tuesday: Microsoft warns vulnerability (CVE-2023-23397) could lead to exploitation before an email is viewed in the Preview Pane.


A researcher at IOActive discovered that home security systems from SimpliSafe are plagued by a vulnerability that allows tech savvy burglars to remotely disable...


The latest Chrome update brings patches for eight vulnerabilities, including seven reported by external researchers.


Patch Tuesday: Microsoft calls attention to a series of zero-day remote code execution attacks hitting its Office productivity suite.