COMMAND

    jidentd

SYSTEMS AFFECTED

    Linux with jidentd 1.0

PROBLEM

    On the Linux  Security Audit Project  mailing list there  has been
    some  discussion  about  anecdotal  evidence  of  machines   being
    exploited via  various identd  daemons.   Chris Evans  looked over
    some  of  the  commonly  used  identd  daemons  and found a likely
    remote-exploitable buffer  overrun in  jidentd 1.0  by Josh Lehan.
    Mitchell  Blank  looked  over  the  code  and  found several other
    potential problems - some serious, some not.  Included is a  patch
    for all the problems Chris and Mitchell Blank spotted.

    Jidentd is linux-specific.   There is a  copy in the  contrib area
    of RedHat's  FTP site.   It is  apparently popular  among the  irc
    crowd due to its ability to provide fake responses to queries.  It
    is believed that it often is run as root.  When run in  standalone
    mode it provides no mechanism to drop privilege after binding  its
    socket.  The code is, frankly, pretty messy.

SOLUTION

    It is recommended not to use jidentd if possible.  If you must run
    it consider applying this patch.  Also, run it from inetd and  NOT
    AS ROOT!  Patch:

    ---
    Content-Type: application/octet-stream; name="jidentd.patch.gz"
    Content-Transfer-Encoding: base64
    Content-Disposition: inline; filename="jidentd.patch.gz"
    Content-MD5: zsLWc7p5oxeCArcm4JlDJA==

    H4sICOxT+TUAAGppZGVudGQA3DxrV9vIkp89v6LNPQk2yGD5hQ1x5hJsEp9lDANksrPJHI6w
    2lgbWfJIMgw3N/99q6ofatkyj5BkMzeHgNTP6np1VXW1XG88ZpVRxP7Xc3mQuBV7q7otn7dG
    Zunmyf75wZu07qeNjY38XoWzecD251esVmXV5m69sVuvMbvTaf5UqVTuGrLwjrvsjM8Y6zC7
    vWvv7Dbb2LGNc5n/aG7btuwWo1ccF187DJ4qPzFW6HlxEnmX88QLg+1ROLuNvKtJsssGbOY7
    I86SiRezWRReRc6UzQOXR1DEsSdb8e/18C07mV/63ogdeSMexJyVrmssjJjvJDwqQ9+N7Z82
    2fZG4YyP5pGX3LKZk4wmPGaO68LKLm/Z1IOCf157l1thdMXsauWsf1LBFW4xNgwZD9wwivkU
    0AEjsY1COM5CCrPdOFHkBDC4N535Hne3qOU2TA8//3D52As4Ozk9fj3c/6XP1iRy14zK3/qn
    Z4PjIVsDEqzlorZmWzUDtbWGVa8q1P7DC0b+3OXsRXwbbyfelG9NXi6V3zheslge8ASmT7a9
    AGs2jRonmjnbWLc0VOJ6YU6hDxhcLnWiKyzNXVHHqjfSFdXrVr2TuyI/vFoceXbjLk3mXQWO
    v7gMHkWBhNZA99Fg//RwcAS02ObJSHO77zmRSZU3g14/p9nEA94J8snUsK1mNV1Uo2W1anpR
    ctjhMasar7/3z5iN8CHcY6pKbmccakEKcFXAp6OJE7FD37naKxS2N9i1E3nOpc+pYSxYLb/P
    q9uE7+XVxpMwSti7MHJzq/0wuGK/zh2oBbC4H3P4q1pdXMzb7E5wFtsKMDKloCjE7JlSUEvp
    rIHrjQXhvCBhZ+HoI08OexY7CIOAj+ARQQelMh8lLIZakOnowguopWi1l0uknbrVtgWRxDLY
    vn/j3MZHHmddII9YlUNlzLkOPZfNYw8QEnHHZ4Ez5T8LnFPf33h0GcZmzxvQNJy5PHE8H3Dp
    BeOQJSETrGx2PY/myWQ8942+rhcTKuexc8UZKBtkyjGMsw1sx/GBBigK8r6RZe9fvT08G/xP
    /489HANLCMzYaHokx0mbqprzg5OFCsI5rbsfuCVE/ilPDkKXo0qFCc5DdsnZKARuiROQCYtN
    nGvU4FyrRd8JXDbhEWf8mke3DLUS8xL259xLCCwUj3bT6tSVePxnEQJGUupjbyUJoJFSRSup
    AW2gSDT5HnTJ3ddrVctuVJXI4J587VzEiRMlJdDwscXGYTR1kjKBWGGIv8T5CKA4EeEOWoOg
    zsdjSyIfaoL1BMALXJ/mR46gfr0Q2HZ4fA7Y4KOPODALAdKxH94UZavreBbB4selsyRSU1sM
    AQEAoB60aOkk8kLa8LuA4+PXF/3T0zLWfcJfxFWuy2B3gOFBTpDGFnNhaoRqeWY5cQGUzchJ
    xLxrbE1MlymFZxq11I+isqj/TI0QaSsAY//+Nytp7u3SjvD8OVtsORgeHiOhC4UCdOjxy/nV
    0bXPXrKqKBWY1RMAhM/iNYsBWGXkLpo92wsKC2OJS9isAXDo1IW52DO3y57FHwLon44nRmJy
    MUBT0NAliXbGPgubr16zbLARpVDfwyrfFCebSO1NQe3HcyN2vI4Dk9Ni718cuudxHbZeyXZY
    KSDJZTwGHWHOsRRAakeqYAOaAT+J0QviBdRBhsVkpTcusRrbxDqfByXRtpwWIOnYC2MFAioF
    Vg5jL5fLQWXVZ/ojfj+I/Vbw3+MZsIgitZoLcxVYYwc8kx2lwAqoPm3ZnjQWKdV9sB/OQ5ik
    hDYIvVpCKW8QxiqoY8GsAKUApHJYvVa5BMINTpCmERATNxcHUY57VIlvXW2BRV/rbLWaW3a1
    umW3OmtloUpIDaH9w17ZFntVg/91+N8Qew8MM0WGhcG5E9+SKpI6T3SXutKJ4/kU57rh68Da
    YPr8cvaqMvaATqwEtvtNGH0sg5MDmyBMxaOi0qCvbOAjXB97+RJ8CVJTr2pQVlKFdqvMnrPq
    X4eHorJuVrazdQ01mFEoIUSVyoIwV6cKRpQQZVT62rPJfMv4D0yQRVN5D1GAilVtiK95chSO
    EAraFw97cks89Hw/RsxAreNj/fYJWr60938SKqvVtOwd6U3lcs8O6LSdtuYecGV5ae0gnPsu
    qo0rnoC9DKOzSRgnaJXsrgk9qecEBAVJOPFLaJr25tPp7RbYMRfINlsx/TE6EHyiQ7zQYQZV
    QgJSXtWTWGKNQwBAjNaTOG0CRqmK+JSB8/oM9DCO1QXkkozpnvLxREyk5AOxtANYamtr7YdA
    AkhaMJrdlgzo0WW9gF5OzixlCzsxVpJqUHer2KwsRtRF75calRkgAc2x9Q/V9a+L31yma7cs
    u1O7i+kiPg1BtBcRfkrFj8G46PFIvkunsZh4zuc8UbcaNWlf9SyQU8hwXwdjSZ27uO//AxuK
    Ac01PIYD034pC6Zl75eb3c2ET0Z1bpymtmPV6nXFiKRtD8ABS7jwyEtYIrXtGYeNcT7Tvjop
    fC8YhbRLjYTf7oF/ovQvmqWgrofz6RG5LLEyC2GwEU3CnIANgoRHgFby8rlU3gU9SVeWl/YP
    wSDsn4OhcHzwXxdn56f9/V8sMDT2RMys3rBqDR01+8YLsVjCp7NvtJxcOtVbsDzbjBHWrVrT
    TgOwklNgB10Tk0mYXDBn3e4zl3hEgZEV5Db0eUdGxhWs3WFJJKwSZC+m2GuA8TGt2dAyRBTA
    emyyGWPAKQwezpJSGss5Oz66wOWJZV6c9t+e9fd7vVOLPcfOyugu4UuZbE+JzksPHFkwkMBW
    Qv8WfO3huQAnRSfJ3diZev4tmigCnXuZWkP6oclgiHNf7A9/X4HjZseqdapZWfC5Ex2B1Jv8
    Q4Vod8zmCbsEV4NHJqtc/otHYWmAta/m4IZIZ1/gnIpPyNRXLUgx0AuIrQPWTFd1QX2gwiRo
    VCFRgLuATZ0EWXX49uhI2rDbSsqL0mSKnMsM5xdNzncMLmfw42S49RO5bhiVA/IgxwoqLQfj
    tJ+ng3bQ2hmNeIYLFjuyjfJz7ABcgBMIvKD/kI7yQjkQtBOcROGlz6dy5KyM0k5QxGUXDCtR
    jyS0LtQAanNqsLInfRvlcYIwDJZ1ARtH4ZSR05PZDxcG6PVfvX0NI7yNd6ExCg97Uam8ZOcT
    PlUlGYtBuEnabFitxiW0qGuQ/Za5DypTbk3NjyLFVw95MppQjTCgleuDRZKrT7njguMDggee
    B58CxtENwgZozIvpCAmOiEG6PB5F3iwBngSKEePQKFPwAWIS2yRyPB/ReHC6fXQoOnuJbrqP
    Dg40NaBehyl9UFvuLbvkPADX3cfYnowo1loooI2sjv8KAio3YlXwGEEtLfb9MpFFonyhxFZY
    tRt+tFjF7o4pEvqDifAnIceGjPRPT62HyHShEPFkHgWwNBkXgF+yqPoI/raoBT4d8eBvwex5
    u1O9alt1dQDLEK9Mhl3eOV5yGBqqzWLn3pSH86TMil0VQNTIrNExQiJawGxQRcimVmB0B2gZ
    I1jmgEoa5JPgfxkvFHTHfi/0bJ/EcNrE6IBO7Acu4oeQC/TBHsouoe5yuMKUT8nvI9KlUqoF
    srIgqaA+oen7nPrUli7KgZFepeUxV41O3UyJ3wSRv6/potJgIoankaQpYvI3FdBRHJ2XVptW
    vaat2a9ObB2yM8nJXrKSlJKKXWbl5dV3lRSRlvvPZ5iF/fRRZMyVYTwWrzdTtz9dr12FBb8B
    hXF0aLEANg4xKKwf1qtmX7XS/EWKVd65wByRwPabzAadL5/KeUOnuAOBuL+lIT35jVkWldU9
    mTZQB3wZgYEfGV8GO53os5TvgalcTqvvWPVG3eA0ZEo8jChtkH7CZUXrZdQOB+CP3XDYeSj1
    RegJ0efTKqSrLiSeCfYRWM8iicT/PvxQSWUZW5VctGxKxmjAZtjYMRjjB1seKsgvX2IuRZtV
    q97saIp+lnabqTAHhsGrQ/EYAdDCwW4mTgJrA08/XdMKKUn9VoydomwYbqkWDHHu5QXxPHKC
    EZeeyBe4ubgYydRi11pYh2EwEws0G1Y9zb/5DvhQFmSKD2M3vAcfizvJAxeaxwgNu2E1ajrF
    hZg4zwU942L7zBxH7goX9pz/JeM4wqUccg9s2IhR/hsHSZInNvGKox3AR1GuTJ3tEIrwbIdZ
    5PbuMrDzj08ZzvghEmd94Mi+4REXT+eYqGAJCdDw0AZLmR2mMSG8NHHYiUqQTB3zPSdqLNJD
    smexySQK51cTsteF+0SuBiVz2TuAVe1bPh2r+nTZdDHxWWiRvyemcvmx1rIa9dqD+RHj98hD
    XTwDht+wXH22cDdDvT3rnw56+DAc/HcuugSOUpylI39tdM1jHtFKHsJbYPY16q0H89a9GHoE
    a/0dcZbLZQ2QT2P7W/BwRmom9EOEy65ydLE6/ujN2MyJMREDz8996eirhjKBZnzFk7hkbn4W
    njHzMpICIzflhakX9pyWDqT7YfgRSUnhH9Kog5P1eJexZ23/L/EbqSC9kfSQNz3QUtYDwnYz
    ASDugK5oQCeMGgXRDkB0gCocgNllH9aA/GtEfmV4CgZt2laj1UrNqW+MXINlF/GrI0bjkY/Z
    QSWq31vE++byhv/dkL8M/VPwn8vsO6BS200j1bhdtxpp5BNtxufPGR6Ni5PMrhbnMiZS4ZGl
    WUGCLQXzU9bPbgCAPS/C5Pkw9C0W+i6bOgHYPUBHylIpAsaE0/0W5HfQUzlCgkAmfTLBuYLI
    4yEqQful1iYAv4dz9svg7KzfK5IRZtqC4FUjkwUhqQ+g6TxwlYWUi7tO02pWtXkkErecOM4X
    YVvrVHnYi2sUwXfqVHnJZjcXARVggr8yVzNWXBqMRFo1qw2raacnc18PABVsVk3KEhLorYre
    5zdimVPlJbDz8Ni0a1azVk0VLhvEpLjZLVALI9JAB9/jeEaHJdKpIpGkvPoNpDXNR0WoDLpA
    vhlsEypXFkgfraX5iyXRSKKJkgTv18iG0GXjMCJlsVmDZZghhC9cBrCwiChHPH7UojJrStVb
    Tmi7IOLbMY54h7ahDllxEkdDOBt1X9JGi4jJpXetDvTuZOQGJn1v7OzSz0FOCtYFG+e30KyW
    yePxuCsYm9byUGlqAP0anYw0fUuwdGaQLDZkTBW9z23zBRJWB4wbJs0pdYpZtQucFlxxVxiC
    FbtLfzHRTmi/Sq0L1jqzu5isLsIa2KJonN6arCuzFyhsSW/EyGfRiBaj6PCHxXpxki1S8Ykl
    XlcZ8YrXWR6vLxgS5BcLLwPtCNqgU1Pi0VZOUeT+9lbnIBaVi6qD1HE8cgLtWcTCa5OI0Ms3
    ElplqBfTWWlbJZ6Zzkq6S6qsFc5IMVXLInguoDSCxlBny7i6Qo3Y3mBvwysFvf6wgha7AjyH
    SyWUSwJUXLkBy3j/wn6aZSkdckBa08HqSRSOQE0OkpLQe4OgLASyWbda1dQU+cZce8rjuW+w
    7YbG/YbGxMbMYqPvy6sCLJhDKvBHG4lILsyeUYExOQIrbcxIlbF1sQHK1w8JvJfZDKOD+uxG
    VwYLjavUeBQGiRfMBS4LEm8w5cyYUI5SlDMik8tXmtF8D+iduqo7mqJOzaeBG8EkG3IWBMmI
    oAu4R+aI+pVGMeVGD5iB9QHY+SzPnJPsijXSMrOr96Xpn46g+xD1eRlFGtA7dM2ShUcqZ1Hj
    KG1e/UMzhaiUbVIetlVk+xKY/aN8+XyvArpjqyykm2V+s4VzFQ1KVRZISLJabNHoURIrdcQX
    q7XczbkFm3OrnbpgrWrbaqUBwvTKjxPFlKITl2Cs9Az2k7w2UoIpUqkUEO+pmyvnqAXh54Yu
    bSX0G7YCF63RS84cmfda4X/N/NBLqBvLBIyjOYafk8k8xtMPmApGwwt0/i1d87Tg95XqpgfY
    VrBJGwkBfwmOSzVznWUpZ6PHEz5K8AIpeIYwgUzKlcAxJ8E8vkRlShXXrEymFI2JdzNqItNv
    U9E2NxamQ0d0WTxO0EynWD0g6ZbFPEiUO425iepkGSNofbo+szYY/rZ/NOhVTo5Pz9cyAYT8
    AFOr2bFa6S2SNIEmcZJ5avLrsyKAcUjHjnJ7wEWLGFYxdWKRScUAwNtpjkrmnFykmgkIpcqR
    XV6mvITQp6xrdELW3LGb1k69nokvLoK+uTI/bnNlfpwg0tPy4zafmh+3qYM09+THCWhX58dt
    LpzCbLJvSU8jq+xpBM7l1Rbw6o6RRwCrRuML/VnQAuLCkBvi8RV+wUDdH8LbtT6v/DnHu6HT
    0OXK20U9ppYF2wFurWfU9ldqKm7oyWwHY494DGd/NnWm7EgpFMTAdWDgRhoy+aHXs4KyKxeY
    R8Adu0MSqwgYzhK0jbvScg8xI84VO7O+cxvzBPEBxqyDeyXao/oaeIX8WdynU2tX3VAu7xnV
    aZBC3U3OVMv7yZa6lUyVBt+Wjmck7F28lIG53vvR1chi8Psa5Cf+07kOJsnubNfb9XfHu+7u
    mjgd6B8f5sRGa1LkZoLtUerWn43WWelZXKZ4I23RZTGlPNtA1DiRRHkhvsHve5TMdpkg58gB
    t2o9Xt9l4ulsfVfwWxv4zQin3o3+H2/53S6lkf7M1tZ22ZMxksugzaq106qZmUq4dVd1ToMQ
    Gzo7Psa7Cwdv+j2dWCHG9vQsA5hFwK/MyZRNBfiWmQuwMIk5pq/HPFoaM+Xtx4051mMeLo2p
    BeJxQyZ6yHMYUrQSeiE6D4fzaUkN93wheY8+nGDbVrvWMoP93xj3ykRXNbQ6ne+iP3+Q2ywT
    93o6zVJvQVRkQdEfWchtdj8ojyG1mkKWZwFRH3LIa3Q/GF/MHrmiSsrM+C5Nu9Gx2s1mJk3+
    F8cLjsJwprPkSR/MPPciYYdh9JHTV1nIalQBbr2Z/Tr3kv0xaEhz4/yUD0sHpq4ahkl6l5sS
    XXwwqHBHhz0Vj4CjW8yzYk7E0dIfAxyoBTe2RX6qkRBf3tP3jWVuelkxfC9M22AjqU65yO4m
    jzHO3sUimDBfrCDQ1WpY7R3D+HgKzOBTmWAjxip2ORd4YqTsMbmoVt7Kk1aWR512dcdq242U
    OiLmBPCJlKWxF+AxvQ98orArtw2Cn7wxYFqVTSyyBS7nlD914wR0XSvmPthLAOHtjXOrl2lm
    Lqe3CqqSrelrLo5H2MQPl2hdJtBzFk55MkEsT5zZjOMXjMR+jH2guKjzPTWwSBYWjsfgQY+g
    KfnT8gMQmGtguC2YEi26mZ7AOUyEE9ZAGug81Nna2hJegGQa/MxQu50yzXdDpTggykPmXh4e
    NfqZPBqyVWJ3IRsfTBsZaeSPIID06GXIS0YQDJSiWFziGIJjDXyqb1zkCI78UEUK6Xckc64E
    2W2rXW/lpdUKLSpDcUzE2QQO0SUl6FK2NkzAA6pyAMxrLhxN+qLMgvpTHcPFkoxl8DmFaQmE
    GWqsJB+GE1EngLAEtOsxOxn06KaxOP0XC9TgxT7ns1JTv+N1mP2DPjs4HvYG5/i9O2Tqn39m
    7J1iaSRJSqZrLnvCNjRC1IFzs0C1y1tM7QaHK0S5EGKTRLeqHwxDHEDpQxj4M7o6V7DjATX1
    gj8XzGgiyXCnZnWquUnEDyOmZE4KSmZv1t5P469ITwMMlonfPJXQOXjLFYpGk+wNJRR3RM1q
    FDySGBSSGiGRMIEfo3s/6xzcEw8dMFQwYKSUKjbeNKMxLfZuePxmf/g6PWKntkJfUNzfvDMq
    VRQdDNK0gAB1v0yTGwdItZ6pIQTl5M4LCGIuNI2VPhTawmLQX9+jA9KAEuXqg0Pq4iGSmj5i
    GJdk1K5jt6xOGrX7OmhT21CaaPBQROZh0jhNoG8tYl3/4M3gqFdm5lnBgzEuTxWMqdSHggwj
    +Uvxb+SEPYgI7l3fYnXDu77GCrXE+it6fukXWbGr+U3W1i78NGqrv8naqlkt/ema/xsE5IIm
    mkHHlIJDAgh0M8FjRcBghoBQYKK3AYnYKSRCti4qwQ69UwJtlSwuAa3yA/ZpMI7PRJgJBCFA
    jTB9oMIDNm0BmQWGLNaCjE+Bd6sWpBbpgsWSEoszi0HjeAgXJwLLcJBcMchBStATOPUgsy5g
    D0KzCE09CLGWzl4EAAZ08AsPWAAA

    -----