synergy3-bin

maintainer Thadah · 5 votes · scanned 2026-08-03 00:08:14.047287

MEDIUM

Why flagged This PKGBUILD downloads a prebuilt proprietary binary (a full .pkg.tar.zst containing executables installed to /opt/Synergy and /usr/bin) at build time via a multi-step token-extraction flow: it follows a tracking/redirect permalink from Symless's email marketing domain (email.mg.symless.com), scrapes a token from an HTML page, then fetches the actual binary with that token. There is no checksum verification (source=() and sha256sums=() are both empty), so the downloaded binary cannot be integrity-checked. The binary is then extracted and installed with suid bit (chmod 4755 on chrome-sandbox). While the download is from the official vendor's domain (symless.com), the absence of any checksum, the use of a marketing-email redirect link as the entry point, and the installation of an unverified suid binary constitute a genuine supply-chain risk: the content could be silently swapped at any point in the redirect/token chain with no way for the user to detect it. This is a real medium-severity concern — not clearly malicious, but an executed binary from a source that cannot be verified by the package manager.

Triggered rules

MEDIUM External download from an untrusted host, not in source=() external_download_not_in_source

curl/wget fetches a URL on a non-allowlisted host that is not part of source=(), so it is not checksum-verified by makepkg.

PKGBUILD:36 curl -fsSL -o "${srcdir}/${_pkgfile}" "https://symless.com/synergy/api/download/${_pkgfile}?token=${token}"

MEDIUM AI review llm_review

An AI model (anthropic/claude-4.6-sonnet-20260217) reviewed this and agrees it is MEDIUM (confidence 82%): This PKGBUILD downloads a prebuilt proprietary binary (a full .pkg.tar.zst containing executables installed to /opt/Synergy and /usr/bin) at build time via a multi-step token-extraction flow: it follows a tracking/redirect permalink from Symless's email marketing domain (email.mg.symless.com), scrapes a token from an HTML page, then fetches the actual binary with that token. There is no checksum verification (source=() and sha256sums=() are both empty), so the downloaded binary cannot be integrity-checked. The binary is then extracted and installed with suid bit (chmod 4755 on chrome-sandbox). While the download is from the official vendor's domain (symless.com), the absence of any checksum, the use of a marketing-email redirect link as the entry point, and the installation of an unverified suid binary constitute a genuine supply-chain risk: the content could be silently swapped at any point in the redirect/token chain with no way for the user to detect it. This is a real medium-severity concern — not clearly malicious, but an executed binary from a source that cannot be verified by the package manager.

PKGBUILD

1 offending line(s) highlighted

      1# Maintainers: arraen, thadah
    
      2# Contributor: Vitalii Kuzhdin <vitaliikuzhdin@gmail.com>
    
      3pkgname="synergy3-bin"
    
      4pkgver="3.6.3"
    
      5pkgrel="1"
    
      6pkgdesc="Share a single mouse and keyboard between multiple computers"
    
      7url="https://symless.com/synergy"
    
      8license=('custom:Proprietary')
    
      9arch=("x86_64")
    
      10source=()
    
      11sha256sums=()
    
      12conflicts=('synergy' 'synergy1-bin' 'synergy-git' 'synergy-1.6' 'synergy2-bin' 'synergy3-bin' 'synergy3-beta-bin')
    
      13depends=('openssl' 'alsa-lib' 'libei' 'libnotify' 'nss' 'qt6-base' 'libxkbfile' 'libxtst' 'libappindicator-gtk3' 'libayatana-appindicator')
    
      14optdepends=('pugixml')
    
      15options=("!strip")
    
      16install="${pkgname}.install"
    
      17
    
      18# Anonymous download permalink provided by Symless
    
      19_permalink="https://email.mg.symless.com/c/eJxMjj1PwzAUAH-Ns1HZ7zn-GDw0gggJECBRqXSzXqw2JbEj2xTCr0d0Yry75QYHPgjTBCe0EdAqbXRzcgSDIkNGWC-EFzRwoFaRJm81tzo0owMOiisB3CJyvbHEEbHVEAhRKmSSz8dNWecplLKhNDeTO9W6FIZbBj2D_l-7Ugz5uDLo_TIy6If0Fafkhz9BFEph2Nf0ESLDW3l4PEO8ed6_bA_nRcLr2hHa9odqd6fu3_P-8-nte_fQiXbXZHcJMWWDRgKT3Gdf8xivQxcHvwEAAP__hk5M-A"
    
      20
    
      21_pkgfile="synergy-${pkgver}-linux-noble-x86_64.pkg.tar.zst"
    
      22
    
      23prepare() {
    
      24  curl -fsSL -c "${srcdir}/cookies.txt" -o /dev/null "$_permalink"
    
      25  curl -fsSL -b "${srcdir}/cookies.txt" -o "${srcdir}/page.html" \
    
      26    "https://symless.com/synergy/download/package/synergy-personal-v3/arch-linux/${_pkgfile}"
    
      27
    
      28  local token
    
      29  token=$(grep -oP '(?<=\\"token\\":\\")[^\\"]+' "${srcdir}/page.html" | head -n1)
    
      30  if [[ -z "$token" ]]; then
    
      31    echo "Failed to get download token."
    
      32    return 1
    
      33  fi
    
      34
    
      35  echo "Downloading .pkg.tar.zst file with permalink token..."
    
      36  curl -fsSL -o "${srcdir}/${_pkgfile}" "https://symless.com/synergy/api/download/${_pkgfile}?token=${token}"
    
      37}
    
      38
    
      39package() {
    
      40  # Extract the .tar.zst file keeping permissions
    
      41  bsdtar -xpf "${srcdir}/${_pkgfile}" -C "${pkgdir}/" opt usr
    
      42
    
      43  install -d "${pkgdir}/usr/bin"
    
      44  ln -s /opt/Synergy/synergy "${pkgdir}/usr/bin/synergy"
    
      45  ln -s /opt/Synergy/synergy-core "${pkgdir}/usr/bin/synergy-core"
    
      46
    
      47  # Install the user service and enable it.
    
      48  install -Dm644 "${pkgdir}/opt/Synergy/resources/services/global/synergy.service" "${pkgdir}/etc/systemd/user/synergy.service"
    
      49  install -d "${pkgdir}/etc/systemd/user/graphical-session.target.wants"
    
      50  ln -s /etc/systemd/user/synergy.service "${pkgdir}/etc/systemd/user/graphical-session.target.wants/synergy.service"
    
      51
    
      52  # Install the login service into the system unit directory (disabled).
    
      53  install -Dm644 "${pkgdir}/opt/Synergy/resources/services/system/synergy.service" "${pkgdir}/usr/lib/systemd/system/synergy.service"
    
      54
    
      55  # Add the loginInfo file
    
      56  install -d "${pkgdir}/etc/Synergy"
    
      57  install -m666 /dev/null "${pkgdir}/etc/Synergy/loginInfo"
    
      58
    
      59  chmod 4755 "${pkgdir}/opt/Synergy/chrome-sandbox" || true
    
      60}
    
      61

Scan history

Scanned at (UTC)	Severity	Rules
2026-08-03 00:08:14	MEDIUM	2
2026-08-02 00:16:08	MEDIUM	2
2026-08-01 00:11:18	MEDIUM	2
2026-07-31 00:14:10	MEDIUM	2
2026-07-30 00:17:23	MEDIUM	2
2026-07-29 00:25:53	MEDIUM	2
2026-07-28 00:07:28	MEDIUM	2
2026-07-27 00:24:32	MEDIUM	2
2026-07-26 00:07:32	MEDIUM	2
2026-07-25 00:13:44	MEDIUM	2
2026-07-24 00:02:28	MEDIUM	2
2026-07-23 00:14:47	MEDIUM	2
2026-07-22 00:29:32	MEDIUM	2
2026-07-21 00:24:15	MEDIUM	2
2026-07-20 00:19:49	MEDIUM	2
2026-07-19 00:17:08	MEDIUM	2
2026-07-18 00:14:48	MEDIUM	2
2026-07-17 00:06:16	MEDIUM	2
2026-07-16 00:05:41	MEDIUM	2
2026-07-15 00:09:25	MEDIUM	2