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CVE-2020-15415

From Exploited flaws, HARD’s guide to the flaws being used in attacks · Checked
This article is about a flaw in DrayTek Multiple Vigor Routers. For every flaw being used in attacks, see Exploited flaws; for DrayTek’s, see DrayTek flaws being used in attacks.

CVE-2020-15415 is a security flaw in DrayTek Multiple Vigor Routers, routers for homes and small offices. Attackers can run their own code on DrayTek Multiple Vigor Routers. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 30 Sep 2024.[1]

DrayTek Multiple Vigor Routers is in things households have: home and small-office routers, so the fix matters at home as much as at work. Fixed in version 1.5.1.

Description

CISA calls it an OS command injection in DrayTek Multiple Vigor Routers. In its words: “DrayTek Vigor3900, Vigor2960, and Vigor300B devices contain an OS command injection vulnerability in cgi-bin/mainfunction.cgi/cvmcfgupload that allows for remote code execution via shell metacharacters in a filename when the text/x-python-script content type is used.”[1]

The underlying weakness is OS command injection (CWE-78), in MITRE’s list of common software weaknesses.[2]

It scores 9.8 out of 10 on the Common Vulnerability Scoring System, which rates it critical, scored by NVD using CVSS 3.1.[2]

Affected versions

NVD’s record lists these fixed versions: in each line, everything before the version shown is affected.[2]

ProductFixed in
vigor3900_firmware1.5.1
vigor2960_firmware1.5.1
vigor300b_firmware1.5.1

Every device with DrayTek Multiple Vigor Routers needs the update.

Exploitation

CISA added it to its catalog of known exploited vulnerabilities on 30 Sep 2024, 1,553 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 21 Oct 2024 to fix it.[1]

FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 84%. That’s in the top 1% of the flaws it scores.[4]

CISA assesses it as automatable: attackers can run it against many targets at once.

CISA doesn’t say who was attacked, or how.

Fix

DrayTek has published a fix or advice.[3] CISA’s required action: “Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.”[1]

  1. Update DrayTek Multiple Vigor Routers now.Open the router’s app, or its admin page in a browser, and look for a firmware update. Then turn on automatic updates, so the next fix arrives on its own.
  2. Check you’re on 1.5.1 or later.Fixed in version 1.5.1. Anything older is what attackers are going after.
  3. If the maker has stopped updating it, replace it.Routers stop getting fixes after a few years, and attackers keep a list of the ones that did. If there’s no newer firmware, it won’t be fixed.

Timeline

DateEvent
The flaw is made public in the National Vulnerability Database, with a severity score of 9.8.[2]
CISA adds it to its catalog of flaws known to be used in attacks.[1]
CISA’s deadline for US government agencies to fix it.[1]
FIRST puts the odds of it being used in attacks in the next 30 days at 84%.[4]

See also

Other DrayTek Multiple Vigor Routers flaws

  • CVE-2020-8515: multiple drayTek vigor routers web management page ·

Other DrayTek flaws

Other OS command injection flaws

  • CVE-2026-110447, Collabora Online – Built-in CODE Server: online – built-in CODE server OS command injection ·
  • CVE-2026-106931, EG Secure Solutions SiteGuard Server Edition: OS command injection ·
  • CVE-2026-83549, SonicWall SMA1000 Appliances: OS command injection ·
  • CVE-2026-49869, Kestra OSS: OSS OS command injection ·
  • CVE-2026-73570, Synacor Zimbra Collaboration Suite (ZCS): OS command injection ·

Added the same day

  • CVE-2023-25280, D-Link DIR-820 Router: OS command injection ·
  • CVE-2019-0344, SAP Commerce Cloud: deserialization of untrusted data ·

Every DrayTek flaw on CISA’s list · Everything added in September 2024

References

  1. ^ Cybersecurity and Infrastructure Security Agency. “DrayTek Multiple Vigor Routers OS Command Injection Vulnerability”. Known Exploited Vulnerabilities Catalog, added 30 Sep 2024.
  2. ^ National Institute of Standards and Technology. “CVE-2020-15415 Detail”. National Vulnerability Database, published 30 Jun 2020.
  3. ^ DrayTek. Advisories and fixes: draytek.com, draytek.com.
  4. ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.845, percentile 99.7, 31 Oct 2026.
  5. CVE Program. “CVE-2020-15415”. The official CVE record.

This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.