ZeroHour
CyberScooppublished ()ingested @CyberScoopNews

Fortra cops to exploitation of GoAnywhere file

criticalRansomware exploited in the wildimportance 60CVE-2025-10035

Vulnerabilities mentionedAll →

CVEVulnerabilityCVSSEPSSFlagsAffectedExposurePublished
CVE-2025-10035
Deserialization Flaw in Fortra GoAnywhere MFT License Servlet Enables RCE

CVE-2025-10035 is a critical (CVSS 9.8) deserialization-of-untrusted-data flaw (CWE-502) in the License Servlet of Fortra GoAnywhere Managed File Transfer (MFT). It is triggered when the servlet processes a license response carrying a validly forged signature, causing it to deserialize an arbitrary attacker-controlled object; the CVSS vector indicates the attack is network-based and requires no privileges or user interaction. Successful exploitation can lead to command injection (CWE-77), effectively giving an attacker command execution on the MFT server and access to the files and credentials that flow through it. Any organization running GoAnywhere MFT, which is commonly deployed as a central file-transfer hub, is affected, although specific affected/fixed version ranges are not provided in the available data. Exploitation is confirmed in the wild: the flaw was added to CISA's KEV catalog on 2025-09-29 with known ransomware use, Microsoft attributes attacks to the Storm-1175 ransomware affiliate (Medusa, now reportedly replaced by StormEncryptor), and EPSS assigns a 99.8% probability of exploitation within 30 days.

Do: Apply mitigations or patches per Fortra's vendor instructions immediately, as this is a KEV entry carrying BOD 22-01 requirements for federal agencies (patch or discontinue use if mitigations are unavailable). Because a ransomware affiliate (Storm-1175, using Medusa/StormEncryptor) is actively exploiting it, hunt for compromise: review License Servlet traffic and logs for forged license responses, check for unexpected processes or new accounts, and look for signs of lateral movement. Until patched, restrict or remove internet exposure of GoAnywhere MFT admin and license interfaces.

9.8100% KEV ransomware
  • Fortra GoAnywhere Managed File Transfer (MFT)
moderatelow thousands of internet-exposed GoAnywhere MFT instances (estimate)
Full article740 words · extracted from cyberscoop.com · click to collapse
Skip to main content

Get our latest cybersecurity news first on Google.

Click here!

The vendor belatedly admitted the max-severity vulnerability was actively exploited weeks after researchers and officials confirmed as much independently.

Listen to this article

0:00

Learn more.

Person on ladder looking into large folder with messy paperwork spilling out. (Stock illustration/Getty Images)
Person on ladder looking into large folder with messy paperwork spilling out. (Stock illustration/Getty Images)

Fortra, in its most forceful admission yet, confirmed a maximum-severity defect it disclosed in GoAnywhere MFT has been actively exploited in attacks, yet researchers are still pressing the vendor to be more forthcoming about how attackers obtained a private key required to achieve exploitation.

The vendor published a summary of its investigation into CVE-2025-10035 Thursday, three weeks after it publicly addressed the vulnerability in its file-transfer service for the first time. “At this time, we have a limited number of reports of unauthorized activity related to CVE-2025-10035,” the company said. 

“It is positive to see Fortra increase their transparency surrounding the CVE-2025-10035 saga,” Ben Harris, founder and CEO at watchTowr, told CyberScoop. “However, the mystery remains — watchTowr researchers and others are still unclear how this vulnerability could be exploited without access to a private key that only Fortra is believed to have access to.”

Researchers at watchTowr, Rapid7 and VulnCheck last month rang alarm bells about the private key after they independently confirmed the steps attackers would have to take to achieve exploitation. 

“The fact that Fortra has now opted to confirm ‘unauthorized activity related to CVE-2025-10035,’ confirms yet again that the vulnerability was not theoretical, and that the attacker has somehow circumvented, or satisfied, the cryptographic requirements needed to exploit this vulnerability,” Harris said.

The scope of compromise has continued to grow during the past month as Fortra and researchers continue hunting for evidence of active exploitation. Fortra also shared more details about the timeline and actions it took behind the scenes prior to publicly disclosing and addressing the vulnerability. 

Security staff at Fortra began investigating a potential vulnerability after a customer reported suspicious activity Sept. 11. After inspecting customer logs, the company started notifying potentially impacted customers and reported the malicious activity to law enforcement that same day. 

The vendor also said it found three instances in its cloud-based GoAnywhere MFT environment “with potentially suspicious activity related to the vulnerability.” Fortra said it isolated those instances for further investigation and alerted customers using those managed services of potential exposure. 

The company deployed the patch to cloud-based services it hosts for customers Sept. 17, but it has not described the extent to which the vulnerability has been exploited in on-premises customer environments and Fortra-hosted services. The vendor said it updated all company-hosted instances of GoAnywhere MFT, including infrastructure rebuilds.

Fortra did not answer questions submitted by CyberScoop on Monday.

The Cybersecurity and Infrastructure Security Agency added CVE-2025-10035 to its known exploited vulnerabilities catalog Sept. 29, noting the defect has been used in ransomware campaigns. Microsoft Threat Intelligence followed up on that last week, noting that a cybercriminal group it tracks as Storm-1175 has exploited CVE-2025-10035 to initiate multi-stage attacks including ransomware. 

Fortra repeatedly declined to confirm it was aware of active exploitation in the wake of those reports. The company previously added indicators of compromise to its security advisory, but didn’t say it was aware of reports of unauthorized activity related to the defect until Thursday.

Latest Podcasts

Text extracted automatically; images, tables and formatting may be missing. Original: https://cyberscoop.com/fortra-goanywhere-vulnerability-exploitation/