Malwarebytes said it could take three of four weeks to fix flaws in its consumer product that were found by a Google security researcher.
In the meantime, customers can implement a workaround: those using the premium version of Anti-Malware "should enable self-protection under settings to mitigate all of the reported vulnerabilities," he wrote.
Kleczynski apologized, saying vulnerabilities are a reality that come with software development. "While these things happen, they shouldn’t happen to our users," he wrote.
Google researcher Tavis Ormandy uncovered several issues with the Anti-Malware product, including that it doesn't use encryption when downloading fresh signatures.
That opens the possibility for a man-in-the-middle attack, Ormandy said in an advisory. An attacker could potentially replace the signature file.
Ormandy also found three other issues, including a privilege escalation flaw.
He reported the flaws to Malwarebytes in November and gave the company 90 days to fix them before going public.
Ormandy has been analyzing quite a few security products lately and finding alarming problems. Last month, he found a problem in Trend Micro's antivirus software that could be used to steal stored passwords.
Vulnerabilities in security products are especially dangerous since they often have deep access to a computer's operating system.
Dozens of serious vulnerabilities were found last year in antivirus products from vendors including Kaspersky Lab, ESET, Avast, AVG Technologies and Intel Security (formerly McAfee). Security experts have warned for years that flaws in endpoint protection products pose a big risk.